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

#define NMax 50001

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

struct topografic
{
     int nod;
    topografic *next;
};
int M;
unsigned short int N,A[NMax],V[NMax],S[NMax];
void citire()
{
    f>>N>>M;
    unsigned short int x,y;
    for(int i=1;i<=N;i++)
    {
            A[i]=0;
            V[i]=0;
    }
    for(int i=1;i<=M;i++)
    {
        f>>x>>y;
        A[x]=(A[x]*10)+y;
    }
    f.close();
}
void parcurgere()
{
    topografic *p;
    new topografic;
    p=NULL;
    V[1]=1;
    S[1]=1;
    unsigned short int k=1;
    while(k>0)
    {
        if(A[S[k]]!=0 && V[A[S[k]]%10]==0)
        {
            k++;
            S[k]=A[S[k-1]]%10;
            V[S[k]]++;
            A[S[k-1]]/=10;
        }
        else if(A[S[k]]!=0 && V[A[S[k]]%10]==1)
        {
            A[S[k]]/=10;
        }
        else
        {
            topografic *r;
            r=new topografic;
            r->nod=S[k];
            r->next=p;
            p=r;
            delete r;
            k--;
        }
    }
    while(p!=NULL)
    {
        cout<<p->nod<<" ";
        p=p->next;
    }
    delete p;
}
int main()
{
    citire();
    parcurgere();
    return 0;
}