Connected Components in an Undirected Graph

You are given an undirected graph with n nodes and m edges. The nodes are labeled from 1 to $n$. Each edge connects two distinct nodes. Your task is to compute the number of connected components in the graph.

A connected component is a set of nodes such that there is a path between any two nodes in this set. Formally, if we denote the number of nodes as $n$ and the number of edges as $m$, then you are given $m$ pairs of integers $(u,v)$ indicating that there is an edge between node $u$ and node $v$.

Read the input from standard input (stdin) and output your answer to standard output (stdout).

inputFormat

The input is given in the following format:

$n$ $m$
$u_1$ $v_1$
$u_2$ $v_2$
... 
$u_m$ $v_m$

Here, $n$ is the number of nodes, $m$ is the number of edges, and each subsequent line contains two integers $u$ and $v$ representing an undirected edge between nodes $u$ and $v$.

outputFormat

Output a single integer which is the number of connected components in the graph.

## sample

5 3
1 2
1 3
4 5

2

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