#include <iostream>
#include <fstream>
using namespace std;
const int N=100001,M=1000001;

ifstream fin("bfs.in");
ofstream out("bfs.out");

int vf[M],urm[M],lst[N],coada[M],d[N];
bool ver[N];

int nr,n,m,k;
int st=1;
int dr=0;

void adauga(int x, int y){
    nr++;
    vf[nr]=y;
    urm[nr]=lst[x];
    lst[x]=nr;


}

void bfs(int x)
{
    int p,y;


   coada[++dr]=x;
   for(int i=1;i<=n;i++) d[i]=0;
   d[x]=0;
    while (st<=dr)
    {
        x=coada[st++];
        p=lst[x];
        while(p!=0){

            y=vf[p];
            if(d[y]==0){
                d[y]=1;
                coada[++dr]=y;

            }
            p=urm[p];
        }
    }



}

void citre(){

    fin>>n>>m;
    int a,b;
    for(int i=1;i<=m;i++){
        fin>>a>>b;
        adauga(a,b);

    }

}


int main()
{
    citre();

    bfs(1);
    for(int i=1;i<=dr;i++) out<<coada[i]<<" ";
    out<<endl;

    return 0;
}