#include <fstream>

using namespace std;
ifstream fin("ctc.in");
ofstream fout("ctc.out");
int a[10005][10005], n, m, viz[10005], numar;
void tareconexe(int val);
int main()
{
    int i, j, k, x, y;
    fin >> n >> m;
    for (i = 1; i <= m; i++) {
        fin >> x >> y;
        a[x][y] = 1;
    }
    for (i = 1; i <= n; i++)
        a[i][i] = 1;
    for (k = 1; k <= n; k++)
        for (i = 1; i <= n; i++)
            for (j = 1; j <= n; j++)
                if (a[i][j] == 0)
                    a[i][j] = a[i][k] * a[k][j];
    tareconexe(1);
    fout << numar << "\n";
    tareconexe(2);
    return 0;
}
void tareconexe(int val)
{
    int i, j;
    numar = 0;
    for (i = 1; i <= n; i++)
        if (viz[i] != val) {
            viz[i] = val;
            numar++;
            if (val == 2)
                fout << i << " ";
            for (j = 1; j <= n; j++)
                if (a[i][j] == 1 && a[j][i] == 1 && viz[j] != val) {
                    if (val == 2)
                        fout << j << " ";
                    viz[j] = val;
                }
            if (val == 2)
                fout << "\n";
        }
}