#include<bits/stdc++.h>
using namespace std;
vector<int>a[100005];
int b[100005];
int c[100005];
queue<int>p;
void dfs(int x){
    cout<<x<<" ";
    int p=a[x].size();
    for(int i=0;i<p;i++){
        if(!b[a[x][i]]){
            b[a[x][i]]=1;
            dfs(a[x][i]);
        }
    }
}
int main(){
    int n,m,x,y;
    cin>>n>>m;
    while(m--){
        cin>>x>>y;
        a[x].push_back(y);
    }
    b[1]=1;
    dfs(1);
    cout<<endl;
    p.push(1);
    c[1]=1;
    while(!p.empty()){
		int x=p.front();
		p.pop();
		cout<<x<<" ";
		int s=a[x].size();
		for(int i=0;i<s;i++){
			if(!c[a[x][i]]){
				c[a[x][i]]=1;
				p.push(a[x][i]);
			}
		}
	}
    return 0;
}