Connected Components

Medium#graphs #dfs #union-find· solved by 0 · time limit 2.0 s

An undirected graph has $n$ vertices (numbered $1 \dots n$ ) and $m$ edges. How many connected components does it have?

Input

$n$ and $m$ , then $m$ lines u v.

The number of components.

$1 \le n \le 10^5$ , $0 \le m \le 2 \times 10^5$

Input

Output

Input

3 0

Output