#include <bits/stdc++.h>
using namespace std;
 
void dfs(int node, vector<vector<int>>&g,vector<int>&visited)
{
	cout<<node<<endl;
	visited[node]=1;
	for(auto u:g[node])
	{
		if(visited[u]==0)
		{
			dfs(u,g,visited);
		}
	}
}
int main() {
	// your code goes here
	int n,m;
	cin>>n>>m;
	vector<vector<int>>g(n+1);
 
	vector<int>visited(n+1);
 
	for(int i=1;i<=m;i++)
	{
		int x,y;
		cin>>x>>y;
		g[x].push_back(y);
		g[y].push_back(x);
	}
	dfs(1,g,visited);
 
	return 0;
}

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