#include <fstream>
#include <vector>

using namespace std;

ifstream cin("ctc.in");
ofstream cout("ctc.out");

#define DIM 100001

vector<int> v[DIM], ctc[DIM], a[DIM], S;
int sel[DIM], n, m, x, y, nrcomp;

static inline void dfs(int k) {
    sel[k] = 1; ///marchez nodul ca vizitat;
    for(auto e : v[k])
        if(!sel[e])
            dfs(e);
    S.push_back(k);
}

static inline void dfsGT(int k) {
    sel[k] = 1;
    ctc[nrcomp].push_back(k);
    for(auto e : a[k])
        if(!sel[e])
            dfsGT(e);
}

static inline void Kosaraju() {
    for(int i = 1; i <= n; i++)
        if(!sel[i])
            dfs(i);
    for(int i = 1; i <= n; i++)
        sel[i] = 0;
    for(int i = S.size() - 1; i >= 0; i--)
        if(!sel[S[i]]) {
            nrcomp++;
            dfsGT(S[i]);
        }
}

int main() {
    cin >> n >> m;
    for(int i = 1; i <= m; i++) {
        cin >> x >> y;
        v[x].push_back(y);
        a[y].push_back(x);  ///pentru graful transpus;
    }

    Kosaraju();
    for(int i = 1; i <= nrcomp; i++) {
        for(auto nod : ctc[i])
            cout << nod << " ";
        cout << '\n';
    }

    return 0;
}