#include <bits/stdc++.h>

using namespace std;

int a[101][101], b[101][101], n, viz[101], nrc;

ifstream fin ("componenteconexe.in");
ofstream fout ("componenteconexe.out");

void Citire()
{
    int i, j;
    fin >> n;
    while(fin >> i >> j)
        a[i][j] = a[j][i] = 1;
}

void DFS(int k)
{
    viz[k] = 1;
    b[nrc][k] = 1;
    for(int i = 1; i <= n; i++)
        if(a[k][i] && viz[i] == 0)
            DFS(i);
}

int main()
{
    int x, y, i, j;
    fin >> n;
    while(fin >> x >> y)
        a[x][y] = a[y][x] = 1;
    for(i = 1; i <= n; i++)
        if(!viz[i])
    {
        nrc++;
        DFS(i);
    }
    fout << nrc << "\n";
    for(i = 1; i <= nrc; i++)
        {
            for(j = 1; j <= n; j++)
                if(b[i][j] == 1)
                    fout << j << " ";
            fout <<"\n";
        }
    return 0;
}