#include <iostream>
#include <cstdio>
#define pb push_back
#include <vector>
using namespace std;
FILE* f=fopen("euler.in","r");
FILE* g=fopen("euler.out","w");
int n,m,ok;
vector <int> v[100001];
void st(int x,int y)
{
    for(int i=0;i<v[x].size();i++)
        if(v[x][i]==y)
            v[x].erase(v[x].begin()+i);
}
void fct(int s)
{
    while(!v[s].empty())
    {
        int w=v[s].front();
        st(s,w),st(w,s);
        fct(w);
    }
    if(ok==1)
        fprintf(g,"%d ",s);
    else ok=1;
}
int main()
{
    fscanf(f,"%d%d",&n,&m);
    int x,y;
    for(int i=0;i<m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        v[x].pb(y);
        v[y].pb(x);
    }
    fct(1);
    return 0;
}