#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
typedef vector<int> vi;
vector<vi> List;
vi visited;
void dfs(int s){
    visited[s] = 1;
    for(int i = 0; i<List[s].size(); i++){
        if(visited[List[s][i]] == 0){
            dfs(List[s][i]);
        }
    }
}

int main() {

    int V,E,a,b;

    cin>>V>>E;

    for(int i = 1; i<=E; i++){
        cin>>a>>b;
        List[a].push_back(b);
    }
    List.assign(V+1, vi());
    visited.assign(V+1, 0);
    for(int i = 0; i<V; i++){
        dfs(i);
        cout << i << " ";
        for(int j=0; j<List[i].size(); j++){
            cout << List[i][j] << " ";
        }
        cout<<endl;
    }

    return 0;
}