#include <fstream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <iomanip>

#define NMax 100005
using namespace std;

int n,m,x,y,nr,comp;
int sol[NMax];
vector<int> G[NMax];
stack<int> s;

void elimin(int u,int v){
    for(int i = 0; i < G[u].size(); ++i){
        if(G[u][i] == v){
            G[u].erase(G[u].begin() + i);
        }
    }
}
int main()
{
    freopen("ciclueuler.in","r",stdin);
    freopen("ciclueuler.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i = 1; i <= m; ++i){
        scanf("%d%d",&x,&y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    s.push(1);
    int t = 0;
    while(!s.empty()){
        int nod = s.top();
        if(t >= m)
            break;
        if(G[nod].size() == 0){
            printf("%d ",nod);
            t++;
            s.pop();
        }else{
            s.push(G[nod][G[nod].size() - 1]);
            elimin(G[nod][G[nod].size() - 1],nod);
            G[nod].pop_back();
        }
    }
    return 0;
}