#include <fstream>

#include <vector>
using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
int n,m,i,viz[100001],y,x,nr,ok,j;
vector <int> l[100001];
deque <int> z[100001];
void dfs(int nod){
    int i;
    viz[nod]=1;
    for(i=0;i<l[nod].size();i++)
        if(viz[l[nod][i]]==0)
            dfs(l[nod][i]);
    z.push_back(nod);
}


int main ()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        for(j=0;j<l[x].size();j++)
        if(l[x][j]==y){
            ok=0;
            break;
        }
        l[x].push_back(y);

    }
    for(int i=1;i<=n;i++)
    if(viz[i]==0){
        dfs(i);

    }
    return 0;
}