Connectivity Components - 2

Input

The input consists of two integers, $N$ and $M$ (0 < N \leq 100000, 0 \leq M \leq 100000). The next $M$ lines each contain two integers, $i$ and $j$ (1 \leq i, j \leq 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