#include <cstdio>

using namespace std;

struct vertex

{

int first, dfn, low, col;

}V[2010];

struct edge

{

int endp, next;

}E[4000000];

int ivc, iec, ec = 1, dfn = 1, col = 1, S[2010], sp = 0;

bool ins[2010];

inline int min(int x, int y)

{

return x < y ? x : y;

}

void add_edge(int u, int v)

}

void DFS(int u)

}

int main()

}