Connectivity Components - 2

An undirected, unweighted graph is provided.

Your task is to determine the number of connected components in the graph and list them.

Input

The input consists of two integers, N and M (0 < N ≤ 100000, 0 ≤ M ≤ 100000). The next M lines each contain two integers, i and j (1 ≤ i, j ≤ N), indicating that there is an edge between vertices i and j.

Output

On the first line of the output, print the number of connected components. For each connected component, print two lines: the first line should contain the number of vertices in that component, and the second line should list the vertices in any order.

Examples