Background

zbw was invited to a kindergarten to create problems for children.

Problem Description

Now zbw has $n$ items, numbered from $1 \sim n$. He will tell you $m$ conditions. Each condition contains two numbers $x, y$, meaning that item $x$ and item $y$ are the same.

Because zbw is in a big hurry, he guarantees that every condition he gives is useful; that is, each condition cannot be deduced from the previous conditions.

You need to answer how many different kinds of items there are.

Input Format

The first line contains two integers $n$ and $m$.

Then follow $m$ lines. Each line contains two numbers $x, y$, meaning that item $x$ and item $y$ are the same.

Output Format

Output one integer: the number of different items.

11 8 
1 2
4 3
5 4
1 3
5 6
7 10
5 10
8 9

3

Hint

For $20\%$ of the testdata, $n, m \le 10$.

For $40\%$ of the testdata, $n, m \le 10^3$.

For $60\%$ of the testdata, $n, m \le 10^5$.

For $80\%$ of the testdata, $m \le 10^6$.

For $100\%$ of the testdata, $1 \le n \le 10^{18}$, $1 \le m \le 10^7$.

Translated by ChatGPT 5