#include <iostream>
#include <bits/stdc++.h>
using namespace std;
 
 
void dfs(int node, vector<int> g[], vector<int>& visited, vector<int>& parent){
 
	cout<<node;
	cout<<"\n";
	visited[node]=1;
 
 
	for(auto u: g[node]){
 
		if(visited[u]==0){
			parent[u] = node;
			dfs(u, g, visited, parent);
		}
	}
}
 
 
int main() {
 
	int n;
	cin>>n;
	int e;
	cin>>e;
 
	vector<int> g[n+1];
 
	for(int i=1; i<=e; i++){
		int u,v;
		cin>>u;
		cin>>v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
 
	// visited
	vector<int> visited(n+1, 0);
 
	// parent
	vector<int> parent(n+1, 0);
 
 
 
	dfs(1, g, visited, parent);
 
 
 
 
 
 
 
 
	return 0;
}

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