#D951. 1 or 2
1 or 2
1 or 2
There are N cards placed face down in a row. On each card, an integer 1 or 2 is written.
Let A_i be the integer written on the i-th card.
Your objective is to guess A_1, A_2, ..., A_N correctly.
You know the following facts:
- For each i = 1, 2, ..., M, the value A_{X_i} + A_{Y_i} + Z_i is an even number.
You are a magician and can use the following magic any number of times:
Magic: Choose one card and know the integer A_i written on it. The cost of using this magic is 1.
What is the minimum cost required to determine all of A_1, A_2, ..., A_N?
It is guaranteed that there is no contradiction in given input.
Constraints
- All values in input are integers.
- 2 \leq N \leq 10^5
- 1 \leq M \leq 10^5
- 1 \leq X_i < Y_i \leq N
- 1 \leq Z_i \leq 100
- The pairs (X_i, Y_i) are distinct.
- There is no contradiction in input. (That is, there exist integers A_1, A_2, ..., A_N that satisfy the conditions.)
Input
Input is given from Standard Input in the following format:
N M X_1 Y_1 Z_1 X_2 Y_2 Z_2 \vdots X_M Y_M Z_M
Output
Print the minimum total cost required to determine all of A_1, A_2, ..., A_N.
Examples
Input
3 1 1 2 1
Output
2
Input
6 5 1 2 1 2 3 2 1 3 3 4 5 4 5 6 5
Output
2
Input
100000 1 1 100000 100
Output
99999
inputFormat
input.
Constraints
- All values in input are integers.
- 2 \leq N \leq 10^5
- 1 \leq M \leq 10^5
- 1 \leq X_i < Y_i \leq N
- 1 \leq Z_i \leq 100
- The pairs (X_i, Y_i) are distinct.
- There is no contradiction in input. (That is, there exist integers A_1, A_2, ..., A_N that satisfy the conditions.)
Input
Input is given from Standard Input in the following format:
N M X_1 Y_1 Z_1 X_2 Y_2 Z_2 \vdots X_M Y_M Z_M
outputFormat
Output
Print the minimum total cost required to determine all of A_1, A_2, ..., A_N.
Examples
Input
3 1 1 2 1
Output
2
Input
6 5 1 2 1 2 3 2 1 3 3 4 5 4 5 6 5
Output
2
Input
100000 1 1 100000 100
Output
99999
样例
100000 1
1 100000 100
99999