#include <iostream>
#include <fstream>
#include <vector>
#include <stack>

using namespace std;

ifstream fin("sortaret.in");
ofstream fout("sortaret.out");

int n, m;
vector<int> gra[50041];
void read(){
	fin >> n >> m;
	for(int i = 0; i < m; ++i){
		int a, b;
		fin >> a >> b;
		gra[a].push_back(b);
		gra[b].push_back(a);
	}
}

bool vi[50041];
stack<int> s;
void dfs(int a=1){
	vi[a] = true;
	for(auto b : gra[a]){
		if(!vi[b]){
			dfs(b);
		}
	}
	s.push(a);
}

void write(){
	while(!s.empty()){
		fout << s.top() << " ";
		s.pop();
	}
}

int main(){
	read();
	dfs();
	write();
	return 0;
}