#include <iostream>
#include <vector>
#include <queue>
using namespace std;
typedef vector< int > vi;
typedef vector< vi > vvi;

void topolol(vvi& G,vi& dg,vi& topo){
    priority_queue<int, vector<int>, greater<int> > vs;
    for(int i=0;i<dg.size();++i)
        if(dg[i]==0) vs.push(i);
    int IX = 0;
    while(not vs.empty() ){
        int v = vs.top();
        vs.pop();
        topo[IX++] = v;
        for(int i=0;i<G[v].size();++i){
            int adj = G[v][i];
            --dg[adj];
            if(dg[adj]==0)
                vs.push(adj);
        }
    }
}

int main(){
    int n,m;
    while(cin >> n >> m){
        vvi G(n);
        vi in_dg(n,0);
        while(m--){
            int u,v;
            cin >> u >> v;
            G[u].push_back(v);
            ++in_dg[v];
        }
        vi topo(n);
        topolol(G,in_dg,topo);
        cout << topo[0];
        for(int i=1; i<topo.size(); ++i)
            cout << ' ' << topo[i];
        cout << endl;
    }
}