//sortarea topologica

#include <fstream>
#include <algorithm>
#include <queue>
#include <vector>
using namespace std;

ifstream in("sortaret.in");
ofstream out("sortaret.out");

const int NMAX = 50001;
int pred[NMAX];
vector<int> succ[NMAX];
int n,m;
int main()
{
    int i,x,y,aux;
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>x>>y;
        pred[y]++;\
        succ[x].push_back(y);
    }
    queue<int>q;
    vector<int>sol;
    for(i=1;i<=n;i++)
        if(pred[i]==0)
            q.push(i);
    while(!q.empty())
    {
        aux=q.front();
        sol.push_back(aux);
        for(i=0;i<succ[aux].size();i++)
        {
            pred[succ[aux][i]]--;
            if(pred[succ[aux][i]]==0)
                q.push(succ[aux][i]);
        }
        q.pop();
    }
    /*if(sol.size()<n)
    out<<"-1";
    else
    for(i=0;i<sol.size();i++)
    out<<sol[i]<<" ";*/
    return 0;
}