#include<vector>
#include<iostream>
#include<fstream>

#define NMAX 100005

using namespace std;

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

vector <int> G[NMAX];
int viz[NMAX];

//long long A[NMAX][NMAX], viz[NMAX];
long long N,M,aux1,aux2,cnt=0;
bool DFS(int n)
{
    if(viz[n]<2)
    fout<<n<<" ";
    viz[n]++;
    int nrvecini=G[n].size();
    for(int i=0; i<nrvecini; i++)
    {
        int vecin=G[n][i];
        if(viz[vecin]<2)
            DFS(vecin);

    }
}

int main()
{
    fin>>N>>M;
    for(int i=1; i<=M; i++)
    {
        fin>>aux1>>aux2;

        G[aux1].push_back(aux2);
    }
DFS(1);
}