#include <bits/stdc++.h>
#define st first
#define nd second
#define pb push_back
#define N 50005
using namespace std;
ifstream fin("ciclueuler.in");
ofstream fout("ciclueuler.out");
typedef long long ll;
ll n,x,y,k;
bool m[2*N][2*N];
vector <int> ans;
void euler(int nod)
{
    for(int i=1;i<=n;i++)
    if(m[nod][i])
    {
        m[nod][i]=m[i][nod]=0;
        euler(i);
    }
    ans.pb(nod);
}
int main()
{
    fin>>n>>k;
    for(int i=1;i<=k;i++)
    {
        fin>>x>>y;
        m[x][y]=m[y][x]=1;
    }
    euler(1);
    for(auto it : ans)
        fout<<it<<' ';
    return 0;
}