#include <bits/stdc++.h>
using namespace std;
 
 
void DFS(int start, vector<int> G[], vector<int>& visited) {
    stack<int> stk;
    stk.push(start);  // Start DFS from this node
 
    while (!stk.empty()) {
        int node = stk.top();
        stk.pop();
 
        if (!visited[node]) {
            // If node hasn't been visited, process it
            cout << node << "\n"; // Visit the node (printing here)
            visited[node] = 1;    // Mark it as visited
 
            // Push all unvisited neighbors of the current node onto the stack
            for (auto u : G[node]) {
                if (!visited[u]) {
                    stk.push(u);
                }
            }
        }
    }
}
int main() {
    int n, m;
    cin >> n >> m;  // n = number of nodes, m = number of edges
    vector<int> G[n+1];  // Graph adjacency list (1-based indexing)
 
    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        G[u].push_back(v);  // Add edge u -> v
        G[v].push_back(u);  // Add edge v -> u (since it's undirected)
    }
 
    vector<int> visited(n+1, 0);  // Visited array to track visited nodes
    DFS(1, G, visited);  // Start DFS from node 1
 
    return 0;
}

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