#include <iostream>
#include <algorithm>
#include <vector>
#include <stack>
using namespace std;
const int maxn = 1e5 + 10;
int n, m;
vector<int> graph[maxn];
int discoverable_time[maxn];
int low_link[maxn];
bool on_stack[maxn];
int current_time = 0;
void dfs(int node) {
    discoverable_time[node] = current_time;
    low_link[node] = current_time;
    current_time++;
    on_stack[node] = true;

    static stack<int> st;
    st.push(node);

    for(int i = 0; i < (int) graph[node].size(); i++) {
        int neighbour = graph[node][i];
        if(discoverable_time[neighbour] == -1) {
            dfs(neighbour);
            low_link[node] = min(low_link[node], low_link[neighbour]);
        }
        else if(on_stack[neighbour]) {
            low_link[node] = min(low_link[node], discoverable_time[neighbour]);
        }
    }
    if(low_link[node] == discoverable_time[node]) {
        while(!st.empty()) {
            int t = st.top();
            st.pop();
            on_stack[t] = false;
            cout << t + 1 << " ";
            if(t == node) {
                break;
            }
        }
        cout << endl;
    }
}
void tarjanSCC() {
    for(int i = 0; i < maxn; i++) {
        discoverable_time[i] = -1;
        on_stack[i] = false;
        low_link[i] = -1;
    }
    for(int i = 0; i < n; i++) {
        if(discoverable_time[i] == -1) {
            dfs(i);
        }
    }
}
int main()
{
    cin >> n >> m;

    for(int i = 0; i < m; i++) {
        int a, b;
        cin >> a >> b;
        a--; b--;
        graph[a].push_back(b);
    }
    tarjanSCC();
    return 0;
}