#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using pll = pair<ll, ll>;
using vll = vector<ll>;
using vld = vector<ld>;
using vpll = vector<pll>;
using vvll = vector<vll>;

vvll graph;
vector<bool> visited;

vll dfs(ll v){
    visited[v] = true;
    vll result{v};
    for (ll w : graph[v]) if (!visited[w]){
        vll child = dfs(w);
        result.insert(result.end(), child.begin(), child.end());
    }
    reverse(result.begin(), result.end());
    return result;
}

int main(){
    ll n, m;
    cin >> n >> m;
    graph = vvll(n+1,vll{});
    visited = vector<bool>(n+1,false);
    for (int i=0;i<m;i++){
        ll x, y;
        cin >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    vll result = dfs(1);
    for (ll i : result)
        cout << i << ' ';
    cout << endl;
    return 0;
}