#include <iostream>
#include <vector>
#include <queue>
using namespace std;
int n,m;
int vis[1001000];
int flg[1001000];
vector <int > p[1000005];
queue <int> q;
void solve (int x){
    cout<<x<<' ';
    for(int i=0;i<p[x].size();i++)
    {
        if(!vis[p[x][i]])
        {
            vis[p[x][i]] = 1;
            solve(p[x][i]);
        }
    }
}
int main(){
    cin>>n>>m;
    int u,v;
    for(int i=1;i<=m;i++)
    {
        cin>>u>>v;
        p[u].push_back(v);
    }
    vis[1]=1;
    solve (1);
    cout<<endl;
    flg[1] = 1;
    q.push(1);
    while(!q.empty()){
        int x = q.front();
        q.pop();
        cout<<x<<' ';
        for(int i = 0;i<p[x].size();i++)
            if(!flg[p[x][i]]){
                flg[p[x][i]] = 1;
                q.push(p[x][i]);
            }
    }
    return 0;
}