#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 <cstring>
using namespace std;
typedef int vert;
typedef vert edge;
typedef vector<edge> edges;
typedef vector<edges> graph;
bool augment( graph& G, int v, vector<vert>& matchTo, bool visited[] )
{
for(int i=0; i<G[v].size(); ++i) {
vert u = G[v][i];
if( visited[u] ) continue;
visited[u] = true;
if( matchTo[u]<0 || augment(G, matchTo[u], matchTo, visited) )
{ matchTo[v]=u, matchTo[u]=v; return true; }
}
return false;
}
static const int NV = 100;
int biMatch( graph& G, int L ) // [0,L):left, [L,?):right
{
vector<vert> matchTo(G.size(), -1);
int ans = 0;
for(vert v=0; v<L; ++v) {
bool visited[NV] = {};
if( augment(G, v, matchTo, visited) )
++ans;
}
return ans;
}
class PeopleYouMayKnow { public:
int maximalScore(vector <string> friends, int personA, int personB)
{
int removed = 0;
// A-C-B : C must be removed
int N = friends.size();
int A = personA, B = personB;
for(int C=0; C<N; ++C) if(C!=A && C!=B)
if( friends[A][C]=='Y' && friends[C][B]=='Y' ) {
removed ++;
for(int D=0; D<N; ++D)
friends[C][D] = friends[D][C] = 'N';
}
// A-A1, B1-B : A1-B1 must be disconnected
vector<int> A1;
for(int C=0; C<N; ++C) if(C!=A && C!=B)
if( friends[A][C]=='Y' )
A1.push_back(C);
vector<int> B1;
for(int C=0; C<N; ++C) if(C!=A && C!=B)
if( friends[C][B]=='Y' )
B1.push_back(C);
// == bimatch
graph G(A1.size()+B1.size());
for(int a=0; a<A1.size(); ++a)
for(int b=0; b<B1.size(); ++b)
if( friends[A1[a]][B1[b]]=='Y' )
G[a].push_back( A1.size()+b );
return removed + biMatch(G, A1.size());
}
};
// 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(_, PeopleYouMayKnow().maximalScore(friends, personA, personB));}
int main(){
CASE(0)
string friends_[] = {"NN"
,"NN"};
vector <string> friends(friends_, friends_+sizeof(friends_)/sizeof(*friends_));
int personA = 0;
int personB = 1;
int _ = 0;
END
CASE(1)
string friends_[] = {"NYNN"
,"YNYN"
,"NYNY"
,"NNYN"};
vector <string> friends(friends_, friends_+sizeof(friends_)/sizeof(*friends_));
int personA = 0;
int personB = 3;
int _ = 1;
END
CASE(2)
string friends_[] = {"NYNYYYN"
,"YNYNNYY"
,"NYNNNNY"
,"YNNNNNN"
,"YNNNNYN"
,"YYNNYNY"
,"NYYNNYN"};
vector <string> friends(friends_, friends_+sizeof(friends_)/sizeof(*friends_));
int personA = 2;
int personB = 3;
int _ = 1;
END
CASE(3)
string friends_[] = {"NYYYYNNNN"
,"YNNNNYYYN"
,"YNNNNNNYN"
,"YNNNNNNYN"
,"YNNNNNNNY"
,"NYNNNNNNY"
,"NYNNNNNNY"
,"NYYYNNNNY"
,"NNNNYYYYN"};
vector <string> friends(friends_, friends_+sizeof(friends_)/sizeof(*friends_));
int personA = 8;
int personB = 0;
int _ = 3;
END
}
// END CUT HERE