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

vector<int> adj[100001];
vector<int> sol;
stack<int> st;

int main()
{
    freopen("ciclueuler.in", "r", stdin);
    freopen("ciclueuler.out", "w", stdout);

    int n, m;
    scanf("%d %d ", &n, &m);

    for (int i = 0, x, y; i < m; i++) {
        scanf("%d %d", &x, &y);
        //cout << x << " " << y << endl;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    st.push(1);
    while (!st.empty()) {
        int node = st.top();
        //cout << node << endl;

        if (adj[node].size()) {
            int son = adj[node].back();
            //cout << "son: " << son << endl;

            adj[node].pop_back();
            adj[son].erase(find(adj[son].begin(), adj[son].end(), node));

            st.push(son);

        } else {
            sol.push_back(node);
            st.pop();
        }
    }

    for (int i = 0; i < sol.size() - 1; i++) {
        cout << sol[i] << " ";
    }
    cout << "\n";

    return 0;
}