#include <fstream>
#include <vector>
using namespace std;
ifstream fin("ctc.in");
ofstream fout("ctc.out");
vector<vector<int>> g,gt;
vector<int>s,vec;
int dfs(int nod)
{
    vec[nod]=1;
    for(int i=1;i<=n;i++)
        if(!vec[i])s.push_back(i);
}
int main()
{
    int n ,m,x,y;
    fin>>n>>m;
    while(m--)
    {
        fin>>x>>y;
        g[x].push_back(y);
        gt[y].push_back(x);
    }
    vector<vector<int>>g,gt(n+1);
    vector<int>v,s(n+1);
}