#include <fstream>
#include<vector>
using namespace std;
ifstream f("sortaret.in");
ofstream g("sortaret.out");
vector <int>a[50001];
int main(){
    f>>n>>m;
    for (i=1;i<=m;i++){
        f>>x>>y;
        a[x].push_back(y);
        if (x!=y)
            viz[y]++;
    }
    for (i=1;i<=n;i++)
        nr[i]=a[i].size();
    for (i=1;i<=n;i++)
        if (viz[i]==0){
            u++;
            q[u]=i;
    while (p<=u){

    }



    return 0;
}