#include <bits/stdc++.h>
using namespace std;
 
int main() {
	// your code goes here
	int n, m;
	cin >> n >> m;
	vector<vector<int>> matrix(n+5);
 
	for (int i = 1; i <= m; i++){
		int a, b;
		cin >> a >> b;
		matrix[a].push_back(b);
		matrix[b].push_back(a);
	}
 
	int source = 1; // here we are taking source as 1 because our input will be as source 1.
	// this source will only work with our input.
	// for another input we have to change our source.
 
	// vector<int> used(n+5,0);
	unordered_map<int, int> used;
	queue<int> q;
	q.push(source);
 
	used[source] = 1;
 
	while(!q.empty()){
		int removed = q.front();
		cout << removed << endl;
		q.pop();
 
		for (int i : matrix[removed]){
			if(used[i] == 0){
				q.push(i);
				used[i] = 1;
			}
		}
	}
	return 0;
}

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