#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

vector <int> nod[50001];
long m,n;
int viz[50001];
ifstream f("sortaret.in");
ofstream g("sortaret.out");

void dfs(long crt)
{
    g<<crt<<" ";
    long i,lg=nod[crt].size();
    for (i=0; i<lg; i++)
        if (!viz[nod[crt][i]])
        {
            viz[nod[crt][i]]=1;
            dfs(nod[crt][i]);
        }
}

int main ()
{
    long i,j,a,b;
    f>>n>>m;
    for (i=1; i<=m; i++)
    {
        f>>a>>b;
        nod[a].push_back(b);
    }
    f.close();

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

    g<<"\n";
    g.close();
    return 0;
}