#include<bits/stdc++.h>
using namespace std;
int n,m;
const int N=100005;
vector <int> p[N];
bool s[N];
bool u[N];
queue<int> q;
void dfs(int x){
	cout<<x<<" ";
	for(int i=0;i<p[x].size();i++){
		if(u[p[x][i]]==0){
			u[p[x][i]]=1;
			dfs(p[x][i]);
		}
	}
}
struct ST{
	int a,b;
}c[N*10];
bool cmp(ST x,ST y){
	return x.a<y.b || x.a==y.a && x.b<y.b;
}
int main(){
    cin>>n>>m;
    for(int i=1;i<=m;i++){
    	int x,y;
    	cin>>x>>y;
    	p[x].push_back(y);
	}
	sort(c+1,c+m+1,cmp);
	u[1]=1;
	q.push(1);
	dfs(1);
	cout<<"\n";
	while(q.size()){
		int x=q.front();
		q.pop();
		cout<<x<<" ";
		for(int i=0;i<p[x].size();i++){
			if(s[p[x][i]]==0){
				s[p[x][i]]=1;
				//cout<<p[x][i]<<" ";
				q.push(p[x][i]);
			}
		}
	}
    return 0;
}