#include <bits/stdc++.h>
using namespace std;
void dfs(int node, vector<int> g[], vector<int> &used, vector<int>& parent ){
	cout<<node;
    cout<<"\n";
    used[node] = 1 ; 
    for(int u:g[node]){
    	if(used[u]==0){
    		parent[u]=node;
    		dfs(u,g,used,parent);
    	}
    }
}
int main() {
	int n,m;
	cin>>n>>m;
	vector<int> g[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);
	}
	vector <int> used(n+5,0);
    vector <int> parent(n+5,0);
    dfs(1,g,used,parent); 	
    return 0;
}

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