ADDED   SRM/556-U/1A.cpp
Index: SRM/556-U/1A.cpp
==================================================================
--- SRM/556-U/1A.cpp
+++ SRM/556-U/1A.cpp
@@ -0,0 +1,152 @@
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+#include <numeric>
+#include <iterator>
+#include <functional>
+#include <complex>
+#include <queue>
+#include <stack>
+#include <cmath>
+#include <cassert>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+class LeftRightDigitsGame2 { public:
+	string minNumber(string digits, string lowerBound)
+	{
+		return rec(digits, lowerBound);
+	}
+
+	map<string, string> memo;
+	string rec(const string& digits, const string& lwb)
+	{
+		if(lwb.size() == 0)
+			return lwb;
+		if(memo.count(lwb))
+			return memo[lwb];
+
+		string best = (digits.substr(0,lwb.size())>=lwb ? digits.substr(0,lwb.size()) : "");
+		string minSoFar = string(1, digits[0]);
+		for(int t=1; t<lwb.size(); ++t) {
+			if( digits[t] < lwb[0] )
+			{
+			}
+			else if( digits[t] == lwb[0] )
+			{
+				string tail = digits.substr(t+1, lwb.size()-(t+1));
+
+				string target = lwb.substr(1, t);
+				bool needOneMore = (lwb.substr(t+1) > tail);
+				if(!needOneMore || incr(target)) {
+					string m = minNumber(digits, target);
+					if( m.size() == target.size() ) {
+						string cand = digits[t] + m + tail;
+						if( lwb<=cand && (best.empty() || best > cand) )
+							best = cand;
+					}
+				}
+			}
+			else
+			{
+				string cand = digits[t] + minSoFar + digits.substr(t+1, lwb.size()-(t+1));
+				if( best.empty() || best > cand )
+					best = cand;
+			}
+
+			minSoFar = min(minSoFar+digits[t], digits[t]+minSoFar);
+		}
+		return memo[lwb] = best;
+	}
+
+	bool incr(string& s)
+	{
+		for(int i=s.size()-1 ;; --i)
+		{
+			if(i==-1)
+				return false;
+			if(s[i]<'9') {
+				s[i]++;
+				break;
+			}
+			s[i]='0';
+		}
+		return true;
+	}
+};
+
+// BEGIN CUT HERE
+#include <ctime>
+double start_time; string timer()
+ { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
+ { os << "{ ";
+   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
+   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
+void verify_case(const string& Expected, const string& Received) {
+ bool ok = (Expected == Received);
+ if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
+ cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
+#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
+#define END	 verify_case(_, LeftRightDigitsGame2().minNumber(digits, lowerBound));}
+int main(){
+
+CASE(0)
+	string digits = "565"; 
+	string lowerBound = "556"; 
+	string _ = "556"; 
+END
+CASE(1)
+	string digits = "565"; 
+	string lowerBound = "566"; 
+	string _ = "655"; 
+END
+CASE(2)
+	string digits = "565"; 
+	string lowerBound = "656"; 
+	string _ = ""; 
+END
+CASE(3)
+	string digits = "9876543210"; 
+	string lowerBound = "5565565565"; 
+	string _ = "5678943210"; 
+END
+CASE(4)
+	string digits = "8016352"; 
+	string lowerBound = "1000000"; 
+	string _ = "1086352"; 
+END
+CASE(5)
+	string digits = "93907757041066207580227527897335194812859183833602"; 
+	string lowerBound = "12089579919698667599337853067564506011831210501927"; 
+	string _ = ""; 
+END
+CASE(6)
+	string digits = "1"; 
+	string lowerBound = "2"; 
+	string _ = ""; 
+END
+CASE(6)
+	string digits = "2"; 
+	string lowerBound = "2"; 
+	string _ = "2"; 
+END
+CASE(6)
+	string digits = "3"; 
+	string lowerBound = "2"; 
+	string _ = "3"; 
+END
+CASE(6)
+	string digits = "55555555555555555555555555555555555555555555555555"; 
+	string lowerBound = "55555555555555555555555555555555555555555555555555"; 
+	string _ = "55555555555555555555555555555555555555555555555555"; 
+END
+}
+// END CUT HERE

ADDED   SRM/556-U/1B.cpp
Index: SRM/556-U/1B.cpp
==================================================================
--- SRM/556-U/1B.cpp
+++ SRM/556-U/1B.cpp
@@ -0,0 +1,166 @@
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+#include <numeric>
+#include <iterator>
+#include <functional>
+#include <complex>
+#include <queue>
+#include <stack>
+#include <cmath>
+#include <cassert>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+class XorTravelingSalesman { public:
+	int maxProfit(vector <int> cityValues, vector <string> roads)
+	{
+		vector< vector<bool> > vis(cityValues.size(), vector<bool>(1024, false));
+		rec(0, cityValues[0], cityValues, roads, vis);
+		int best = 0;
+		for(int p=0; p<cityValues.size(); ++p)
+			for(int v=0; v<1024; ++v)
+				if( vis[p][v] )
+					best = max(best, v);
+		return best;
+	}
+
+	void rec(int p, int value, const vector <int>& cityValues, const vector <string>& roads,
+		vector< vector<bool> >& vis)
+	{
+		if(vis[p][value])
+			return;
+		vis[p][value] = true;
+		for(int q=0; q<cityValues.size(); ++q)
+			if(roads[p][q] == 'Y')
+				rec(q, value^cityValues[q], cityValues, roads, vis);
+	}
+};
+
+// BEGIN CUT HERE
+#include <ctime>
+double start_time; string timer()
+ { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
+ { os << "{ ";
+   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
+   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
+void verify_case(const int& Expected, const int& Received) {
+ bool ok = (Expected == Received);
+ if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
+ cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
+#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
+#define END	 verify_case(_, XorTravelingSalesman().maxProfit(cityValues, roads));}
+int main(){
+
+CASE(0)
+	int cityValues_[] = {0, 7, 11, 5, 2};
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = {"NYNYY",
+ "YNYNN",
+ "NYNNN",
+ "YNNNN",
+ "YNNNN"};
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = 14; 
+END
+CASE(1)
+	int cityValues_[] = {556};
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = {"N"};
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = 556; 
+END
+CASE(2)
+	int cityValues_[] = {0, 4, 8, 32, 512};
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = {"NYYYY",
+ "YNNNN",
+ "YNNNN",
+ "YNNNN",
+ "YNNNN"};
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = 556; 
+END
+CASE(3)
+	int cityValues_[] = {37, 1, 19, 64, 42, 41, 64, 64, 54, 16, 256, 36, 64, 2, 4, 2, 62, 29, 58, 64, 1, 32, 16,
+ 256, 17, 2, 17, 4, 1, 64, 21, 8, 256, 63, 3, 1, 43, 15, 8, 39, 41, 8, 16, 8, 16, 256, 64, 512, 45, 64};
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = {"NNNNNNYYYYNNNNNNNNNNNNNNNNNNNNNNNNNYNNNNNNNNNNNNNN",
+ "NNNNNNNNNNNNNNNNYNNNNNNNYNNNNNNNNNNNNNNNNYYNNNYYNN",
+ "NNNNNYYNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN",
+ "NNNNNNNYNNNNNNNNNNYNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN",
+ "NNNNNNNNNNNNNNNYNNYNYNNNNNNYNNNNNNNNNNYNNNNNNNNNNN",
+ "NNYNNNYNNNNNNNNYNNYNNNYYNNNYNYNNNNYNNNNNNNNYNNNNNN",
+ "YNYNNYNYNNNNNNNYNNNNNNNNNNNNNNNNNNNYNNNNNNNNYNNYNN",
+ "YNNYNNYNYNYYNNNNNNNNNNNNNNNNNNNNNNYNNYNNNNNNNNNNNN",
+ "YNNNNNNYNNNNNNNNNNNNNNYNYNNNNNNNNNNYYYNNNNNNNYNNNY",
+ "YNNNNNNNNNNNNNNNNYNYNYNYYNNNYNNNNYNNNNNNNNNNNNNNNY",
+ "NNNNNNNYNNNNYNNNNNNNNYYNNNYYNNNNYNYYNNNNNNNNNNNNNN",
+ "NNNNNNNYNNNNNNYNNNNYYNNNYNNYYNNNNNNNNNNNNNYNYNNNNN",
+ "NNNNNNNNNNYNNNNNYNNNNYNNNNNNNNNNYNYNNYNYNNNYNYNNNN",
+ "NNNNNNNNNNNNNNNYNNNNNNNNNYNNNNNNNNNNNNYNNNNNNNNYNN",
+ "NNNNNNNNNNNYNNNNNYNYNNYYNNNNNYNNNNNNNNNYNNYNNYNNNN",
+ "NNNNYYYNNNNNNYNNNYYNNYNNNYNYYNNNNNNNNNYYYNNYNNYNYN",
+ "NYNNNNNNNNNNYNNNNNNNYNNNYYNNNYNNNNYNNNNNNNNNNNNNNN",
+ "NNNNNNNNNYNNNNYYNNNNNNYNNNYNNNNNYNNYNYYNNNNYNNNYNN",
+ "NNNYYYNNNNNNNNNYNNNNNYNYNYNNNNNNNNYNNNNNNNNNNNNNNN",
+ "NNNNNNNNNYNYNNYNNNNNNYNYYYNNNNNNNNNNNYNNYNNNNNYNNN",
+ "NNNNYNNNNNNYNNNNYNNNNYNNNYYNNNYNNNYNNNNNNNNNNYNYNY",
+ "NNNNNNNNNYYNYNNYNNYYYNYNNNNNNNNYNYNNNNNNNNNNYNNNNN",
+ "NNNNNYNNYNYNNNYNNYNNNYNNNNNNNNNNNYNNYNYNNYNNNNNNNN",
+ "NNNNNYNNNYNNNNYNNNYYNNNNNNNNNNNNNNNNNNNNNNYNNNYNNN",
+ "NYNNNNNNYYNYNNNNYNNYNNNNNNNNNNYNNNNNNYNNNYNNYNNNNN",
+ "NNNNNNNNNNNNNYNYYNYYYNNNNNNYNNNNNNNNNNNYYNNNNNNNYN",
+ "NNNNNNNNNNYNNNNNNYNNYNNNNNNNNYNNNNYNNNNNNYYNNNNYNN",
+ "NNNNYYNNNNYYNNNYNNNNNNNNNYNNNYYNYNNNNNNNNNNNNNNNNN",
+ "NNNNNNNNNYNYNNNYNNNNNNNNNNNNNYNNNNYNNNNNNNNYNNYNYN",
+ "NNNNNYNNNNNNNNYNYNNNNNNNNNYYYNNNNNNNNYNNNNYNNNNNNN",
+ "NNNNNNNNNNNNNNNNNNNNYNNNYNNYNNNNNYNNNNNNNNNNNNNNNY",
+ "NNNNNNNNNNNNNNNNNNNNNYNNNNNNNNNNYNNNNNNNNNYNNNNNNN",
+ "NNNNNNNNNNYNYNNNNYNNNNNNNNNYNNNYNNNYYNNNNNYNNNYNNN",
+ "NNNNNNNNNYNNNNNNNNNNNYYNNNNNNNYNNNNNNNYNNYNNNNNNNN",
+ "NNNNNYNYNNYNYNNNYNYNYNNNNNYNYNNNNNNYYNYNYNYNNNNNYN",
+ "YNNNNNYNYNYNNNNNNYNNNNNNNNNNNNNNYNYNNNNNYNNYNNNYNN",
+ "NNNNNNNNYNNNNNNNNNNNNNYNNNNNNNNNYNYNNNNNNYNNNNNNYN",
+ "NNNNNNNYYNNNYNNNNYNYNNNNYNNNNYNNNNNNNNNNNYNNNNYNNN",
+ "NNNNYNNNNNNNNYNYNYNNNNYNNNNNNNNNNYYNNNNYNNNNNNNNNY",
+ "NNNNNNNNNNNNYNYYNNNNNNNNNYNNNNNNNNNNNNYNNNNNYNYYNN",
+ "NNNNNNNNNNNNNNNYNNNYNNNNNYNNNNNNNNYYNNNNNNNNNNNNNN",
+ "NYNNNNNNNNNNNNNNNNNNNNYNYNYNNNNNNYNNYYNNNNNNNNNNNN",
+ "NYNNNNNNNNNYNNYNNNNNNNNYNNYNNYNYYNYNNNNNNNNNYNNNNN",
+ "NNNNNYNNNNNNYNNYNYNNNNNNNNNNYNNNNNNYNNNNNNNNNNNNNY",
+ "NNNNNNYNNNNYNNNNNNNNNYNNYNNNNNNNNNNNNNNYNNYNNYNNNY",
+ "NNNNNNNNYNNNYNYNNNNNYNNNNNNNNNNNNNNNNNNNNNNNYNNNNN",
+ "NYNNNNNNNNNNNNNYNNNYNNNYNNNNYNNNYNNNNYNYNNNNNNNNNN",
+ "NYNNNNYNNNNNNYNNNYNNYNNNNNYNNNNNNNNYNNNYNNNNNNNNNN",
+ "NNNNNNNNNNNNNNNYNNNNNNNNNYNNYNNNNNYNYNNNNNNNNNNNNN",
+ "NNNNNNNNYYNNNNNNNNNNYNNNNNNNNNYNNNNNNNYNNNNYYNNNNN"};
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = 895; 
+END
+/*
+CASE(4)
+	int cityValues_[] = ;
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = ;
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = ; 
+END
+CASE(5)
+	int cityValues_[] = ;
+	  vector <int> cityValues(cityValues_, cityValues_+sizeof(cityValues_)/sizeof(*cityValues_)); 
+	string roads_[] = ;
+	  vector <string> roads(roads_, roads_+sizeof(roads_)/sizeof(*roads_)); 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/556-U/1C-U.cpp
Index: SRM/556-U/1C-U.cpp
==================================================================
--- SRM/556-U/1C-U.cpp
+++ SRM/556-U/1C-U.cpp
@@ -0,0 +1,244 @@
+#include <iostream>
+#include <sstream>
+#include <iomanip>
+#include <vector>
+#include <string>
+#include <map>
+#include <set>
+#include <algorithm>
+#include <numeric>
+#include <iterator>
+#include <functional>
+#include <complex>
+#include <queue>
+#include <stack>
+#include <cmath>
+#include <cassert>
+using namespace std;
+typedef long long LL;
+typedef long double LD;
+typedef complex<LD> CMP;
+
+template<typename T>
+class IdGen
+{
+	map<T, int> v2id_;
+	vector<T>   id2v_;
+public:
+	int v2id(const T& v) {
+		if( !v2id_.count(v) ) { v2id_[v] = size(); id2v_.push_back(v); }
+		return v2id_[v];
+	}
+	const T& id2v(int i) const { return id2v_[i]; }
+	int size() const { return id2v_.size(); }
+};
+
+template<typename Vert, typename Flow, int NV=2502>
+class MaxFlow
+{
+	IdGen<Vert> idgen;
+	vector<int> G[NV];
+	Flow F[NV][NV];
+
+public:
+	void addEdge( Vert s_, Vert t_, Flow f )
+	{
+		const int s = idgen.v2id(s_), t = idgen.v2id(t_);
+		G[s].push_back(t);
+		G[t].push_back(s);
+		F[s][t] = f;
+		F[t][s] = 0;
+	}
+
+	Flow calc( Vert s_, Vert t_ )
+	{
+		const int S = idgen.v2id(s_), D = idgen.v2id(t_);
+		for( Flow total=0 ;; ) {
+			// Do BFS and compute the level for each node.
+			int LV[NV] = {0};
+			vector<int> Q(1, S);
+			for(int lv=1; !Q.empty(); ++lv) {
+				vector<int> Q2;
+				for(size_t i=0; i!=Q.size(); ++i) {
+					const vector<int>& ne = G[Q[i]];
+					for(size_t j=0; j!=ne.size(); ++j)
+						if( F[Q[i]][ne[j]] && !LV[ne[j]] && ne[j]!=S )
+							LV[ne[j]]=lv, Q2.push_back(ne[j]);
+				}
+				Q.swap(Q2);
+			}
+
+			// Destination is now unreachable. Done.
+			if( !LV[D] )
+				return total;
+
+			// Iterating DFS.
+			bool blocked[NV] = {};
+			total += dinic_dfs( S, D, LV, 0x7fffffff, blocked );
+		}
+	}
+
+private:
+	Flow dinic_dfs( int v, int D, int LV[], Flow flow_in, bool blocked[] )
+	{
+		Flow flow_out = 0;
+		for(size_t i=0; i!=G[v].size(); ++i) {
+			int u = G[v][i];
+			if( LV[v]+1==LV[u] && F[v][u] ) {
+				Flow f = min(flow_in-flow_out, F[v][u]);
+				if( u==D || !blocked[u] && (f=dinic_dfs(u,D,LV,f,blocked))>0 ) {
+					F[v][u]  -= f;
+					F[u][v]  += f;
+					flow_out += f;
+					if( flow_in == flow_out ) return flow_out;
+				}
+			}
+		}
+		blocked[v] = (flow_out==0);
+		return flow_out;
+	}
+};
+
+class OldBridges { public:
+	string isPossible(vector <string> bridges, int a1, int a2, int an, int b1, int b2, int bn)
+	{
+		typedef pair<int,int> Vert;
+		enum {SRC, SINK, VERT, E1, E2};
+		static const int INF = 99999999;
+		MaxFlow<Vert, int>* mf = new MaxFlow<Vert,int>;
+
+		mf->addEdge(Vert(SRC,0), Vert(VERT,a1), 2*an);
+		mf->addEdge(Vert(VERT,a2), Vert(SINK,0), 2*an);
+		mf->addEdge(Vert(SRC,0), Vert(VERT,b1), 2*bn);
+		mf->addEdge(Vert(VERT,b2), Vert(SINK,0), 2*bn);
+
+		int N = bridges.size();
+		for(int a=0; a<N; ++a)
+		for(int b=a+1; b<N; ++b)
+			if(bridges[a][b] == 'N') {
+				mf->addEdge(Vert(VERT,a), Vert(VERT,b), INF);
+				mf->addEdge(Vert(VERT,b), Vert(VERT,a), INF);
+			} else if(bridges[a][b] == 'O') {
+				Vert e1 = Vert(E1, a*N+b);
+				Vert e2 = Vert(E2, a*N+b);
+				mf->addEdge(Vert(VERT,a), e1, 2);
+				mf->addEdge(Vert(VERT,b), e1, 2);
+				mf->addEdge(e1, e2, 2);
+				mf->addEdge(e2, Vert(VERT,a), 2);
+				mf->addEdge(e2, Vert(VERT,b), 2);
+			}
+
+		int flow = mf->calc(Vert(SRC,0), Vert(SINK,0));
+		delete mf;
+		return flow==(an+an+bn+bn) ? "Yes" : "No";
+	}
+};
+
+// BEGIN CUT HERE
+#include <ctime>
+double start_time; string timer()
+ { ostringstream os; os << " (" << int((clock()-start_time)/CLOCKS_PER_SEC*1000) << " msec)"; return os.str(); }
+template<typename T> ostream& operator<<(ostream& os, const vector<T>& v)
+ { os << "{ ";
+   for(typename vector<T>::const_iterator it=v.begin(); it!=v.end(); ++it)
+   os << '\"' << *it << '\"' << (it+1==v.end() ? "" : ", "); os << " }"; return os; }
+void verify_case(const string& Expected, const string& Received) {
+ bool ok = (Expected == Received);
+ if(ok) cerr << "PASSED" << timer() << endl;  else { cerr << "FAILED" << timer() << endl;
+ cerr << "\to: \"" << Expected << '\"' << endl << "\tx: \"" << Received << '\"' << endl; } }
+#define CASE(N) {cerr << "Test Case #" << N << "..." << flush; start_time=clock();
+#define END	 verify_case(_, OldBridges().isPossible(bridges, a1, a2, an, b1, b2, bn));}
+int main(){
+
+CASE(0)
+	string bridges_[] = {"XOXX","OXOX","XOXO","XXOX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 1; 
+	int an = 1; 
+	int b1 = 2; 
+	int b2 = 3; 
+	int bn = 1; 
+	string _ = "Yes"; 
+END
+CASE(1)
+	string bridges_[] = {"XOXX","OXOX","XOXO","XXOX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 2; 
+	int an = 1; 
+	int b1 = 1; 
+	int b2 = 3; 
+	int bn = 1; 
+	string _ = "No"; 
+END
+CASE(2)
+	string bridges_[] = {"XOXO","OXOX","XOXO","OXOX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 2; 
+	int an = 1; 
+	int b1 = 1; 
+	int b2 = 3; 
+	int bn = 1; 
+	string _ = "Yes"; 
+END
+CASE(3)
+	string bridges_[] = {"XNXO","NXOX","XOXO","OXOX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 2; 
+	int an = 1; 
+	int b1 = 1; 
+	int b2 = 3; 
+	int bn = 2; 
+	string _ = "No"; 
+END
+CASE(4)
+	string bridges_[] = {"XOXOO","OXOXO","XOXOO","OXOXO","OOOOX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 2; 
+	int an = 2; 
+	int b1 = 1; 
+	int b2 = 3; 
+	int bn = 2; 
+	string _ = "Yes"; 
+END
+CASE(5)
+	string bridges_[] = {"XOOOX","OXOOX","OOXOX","OOOXN","XXXNX"};
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = 0; 
+	int a2 = 4; 
+	int an = 3; 
+	int b1 = 1; 
+	int b2 = 2; 
+	int bn = 2; 
+	string _ = "No"; 
+END
+/*
+CASE(6)
+	string bridges_[] = ;
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = ; 
+	int a2 = ; 
+	int an = ; 
+	int b1 = ; 
+	int b2 = ; 
+	int bn = ; 
+	string _ = ; 
+END
+CASE(7)
+	string bridges_[] = ;
+	  vector <string> bridges(bridges_, bridges_+sizeof(bridges_)/sizeof(*bridges_)); 
+	int a1 = ; 
+	int a2 = ; 
+	int an = ; 
+	int b1 = ; 
+	int b2 = ; 
+	int bn = ; 
+	string _ = ; 
+END
+*/
+}
+// END CUT HERE