#include <cstdio>
#include <vector>
#include <deque>

using namespace std;
FILE *f,*g;

vector <int> v[50002];
deque <int> coada,q;
bool viz[50002];

void bfs(int nod)
{
    viz[nod]=1;
    q.push_back(nod);
    coada.push_back(nod);
    while(!q.empty())
    {
        nod=q.front();
        q.pop_front();
        for(int i=0;i<v[nod].size();++i)
        {
            int vecin=v[nod][i];
            if(!viz[v[nod][i]])
            {
                viz[v[nod][i]]=1;
                coada.push_back(vecin);
                q.push_back(v[nod][i]);
            }
        }
    }
}
int main()
{
    f=fopen("sortaret.in","r");
    g=fopen("sortaret.out","w");
    int m,n,x,y;
    fscanf(f,"%d %d",&n,&m);
    for(int i=1;i<=m;++i)
    {
        fscanf(f,"%d %d",&x,&y);
        v[x].push_back(y);
    }
    bfs(1);
    while(!coada.empty())
    {
        int nod=coada.front();
        coada.pop_front();
        fprintf(g,"%d ",nod);
    }
    fclose(f);
    fclose(g);

}