ADDED   SRM/672-U/1A-U.cpp
Index: SRM/672-U/1A-U.cpp
==================================================================
--- SRM/672-U/1A-U.cpp
+++ SRM/672-U/1A-U.cpp
@@ -0,0 +1,96 @@
+#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>
+#include <tuple>
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+class Procrastination { public:
+	long long findFinalAssignee(long long n)
+	{
+		map<LL, set<LL>> divs;
+
+		for(LL k=2; k*2<=n; ) {
+			if(n%k==0) ++n;
+			else if(n%k==1) --n;
+
+			set<LL>& dn = divs[n];
+			if(dn.empty())
+				for(LL p=1; p*p<=n; ++p)
+					if(n%p==0) {
+						dn.insert(p);
+						dn.insert(n/p);
+					}
+					else if((n-1)%p==0) {
+						dn.insert(p);
+						dn.insert((n-1)/p);
+					}
+
+			k = *dn.lower_bound(k+1);
+		}
+		return n;
+	}
+};
+
+// 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 long long& Expected, const long long& 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(_, Procrastination().findFinalAssignee(n));}
+int main(){
+
+CASE(0)
+	long long n = 3LL; 
+	long long _ = 3LL; 
+END
+CASE(1)
+	long long n = 8LL; 
+	long long _ = 11LL; 
+END
+CASE(2)
+	long long n = 20LL; 
+	long long _ = 20LL; 
+END
+CASE(3)
+	long long n = 196248LL; 
+	long long _ = 196259LL; 
+END
+CASE(4)
+	long long n = 5587021440LL; 
+	long long _ = 5587021440LL; 
+END
+/*
+CASE(5)
+	long long n = LL; 
+	long long _ = LL; 
+END
+CASE(6)
+	long long n = LL; 
+	long long _ = LL; 
+END
+*/
+}
+// END CUT HERE

ADDED   SRM/672-U/1B-U.cpp
Index: SRM/672-U/1B-U.cpp
==================================================================
--- SRM/672-U/1B-U.cpp
+++ SRM/672-U/1B-U.cpp
@@ -0,0 +1,116 @@
+#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>
+#include <tuple>
+using namespace std;
+typedef long long LL;
+typedef complex<double> CMP;
+
+static const unsigned MODVAL = 1000000007;
+struct mint
+{
+	unsigned val;
+	mint():val(0){}
+	mint(int      x):val(x%MODVAL) {}
+	mint(unsigned x):val(x%MODVAL) {}
+	mint(LL       x):val(x%MODVAL) {}
+};
+mint& operator+=(mint& x, mint y) { return x = x.val+y.val; }
+mint& operator-=(mint& x, mint y) { return x = x.val-y.val+MODVAL; }
+mint& operator*=(mint& x, mint y) { return x = LL(x.val)*y.val; }
+mint operator+(mint x, mint y) { return x+=y; }
+mint operator-(mint x, mint y) { return x-=y; }
+mint operator*(mint x, mint y) { return x*=y; }
+mint POW(mint x, LL e) { mint v=1; for(;e;x*=x,e>>=1) if(e&1) v*=x; return v; }
+mint& operator/=(mint& x, mint y) { return x *= POW(y, MODVAL-2); }
+mint operator/(mint x, mint y) { return x/=y; }
+vector<mint> FAC_(1,1);
+mint FAC(LL n) { while( FAC_.size()<=n ) FAC_.push_back( FAC_.back()*LL(FAC_.size()) ); return FAC_[n]; }
+
+// nCk :: O(1) time, O(n^2) space.
+vector< vector<mint> > CP_;
+mint C(int n, int k) {
+	while( CP_.size() <= n ) {
+		int nn = CP_.size();
+		CP_.push_back(vector<mint>(nn+1,1));
+		for(int kk=1; kk<nn; ++kk)
+			CP_[nn][kk] = CP_[nn-1][kk-1] + CP_[nn-1][kk];
+	}
+	return k<0 || n<k ? 0 : CP_[n][k];
+}
+
+class AlmostEulerianGraph { public:
+	int calculateGraphs(int n)
+	{
+		memo.assign(n+1, -1);
+		return (calcExactEulerian(n) * (LL(n)*(n-1)/2+1)).val;
+	}
+
+	vector<int> memo;
+	mint calcExactEulerian(int n)
+	{
+		if(n == 1)
+			return 1;
+		if(memo[n] != -1)
+			return memo[n];
+
+		mint sum = 0;
+		for(int k=1; k<n; ++k)
+			sum += k * C(n, k) * POW(2, C(n-k-1, 2).val) * calcExactEulerian(k);
+		return memo[n] = (POW(2, C(n-1, 2).val) - sum/n).val;
+	}
+};
+
+// 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(_, AlmostEulerianGraph().calculateGraphs(n));}
+int main(){
+
+CASE(0)
+	int n = 3; 
+	int _ = 4; 
+END
+CASE(1)
+	int n = 2; 
+	int _ = 0; 
+END
+CASE(2)
+	int n = 42; 
+	int _ = 29010676; 
+END
+CASE(3)
+	int n = 2000; 
+	int _ = -1; 
+END
+/*
+CASE(4)
+	int n = ; 
+	int _ = ; 
+END
+*/
+}
+// END CUT HERE