#include<bits/stdc++.h>
using namespace std;
vector<pair<int , int> > v;
queue<int> q;
bool vis[100010] , vis1[100010];
int n , m;
void dfs(int x){
	if(vis[x] == 1) return;
	vis[x] = 1;
	cout << x << " ";
	for(int i = 0; i < m; i++){
		if(x == v[i].first){
			dfs(v[i].second);
		}
	}
}
int main(){
	cin >> n >> m;
	for(int i = 1; i <= m; i++){
		int a , b;
		cin >> a >> b;
		v.push_back(make_pair(a , b));
	}
	sort(v.begin() , v.end());
	dfs(1);
	q.push(1);
	cout << endl;
	while(!q.empty()){
		cout << q.front() << " ";
		int qtop = q.front();
		q.pop();
		for(int i = 0; i < m; i++){
			if(qtop == v[i].first and vis1[v[i].second] == 0){
				vis1[v[i].second] = 1;
				q.push(v[i].second);
			}
		}
	}
}