#include <bits/stdc++.h>
#define Nmax 50005
#define inf 1<<30

using namespace std;

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

vector <int> mat[Nmax];
int n,m,x,y,p[Nmax],sol[Nmax];

void dfs(int nod)
{
    fout<<nod<<" ";
    for(int i=0;i<mat[nod].size();i++)
    {
        y=mat[nod][i];
        if(p[y]>p[nod])
        {
            p[y]=p[nod]+1;
            dfs(y);
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        mat[x].push_back(y);
    }
    for(int i=2;i<=n;i++)
        p[i]=inf;
    p[1]=1;
    dfs(1);
    return 0;
}