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
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;

/**
 * https://beta.atcoder.jp/contests/abc077/tasks/arc084_b
 */
public class Main {

	static Node nodes[];
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int N = Integer.parseInt(sc.next());
		int M = Integer.parseInt(sc.next());
		nodes = new Node[N];
		for(int i=0; i<N; i++) {
			nodes[i] = new Node(i);
		}

		for(int i=0; i<M; i++){
			Node x = nodes[Integer.parseInt(sc.next()) - 1];
			Node y = nodes[Integer.parseInt(sc.next()) - 1];
			int z = Integer.parseInt(sc.next());
			x.neighbor.put(y, z);
			y.neighbor.put(x, z);
		}
		sc.close();
		
		int ans = assignColor(nodes);
		System.out.println(ans);
	}
	
	static class Node{
		int id;
		Map<Node,Integer> neighbor = new HashMap<>();
		int color = -1;
		Node(int id){
			this.id = id;
		}
	}
	
	static int assignColor(Node[] nodeList){
		int color = 0;
		for(Node node:nodeList){
			if(node.color==-1){
				List<Node> que = new ArrayList<>();
				node.color = color;
				que.add(node);
				while(que.size()>0){
					for(Node n: que.remove(0).neighbor.keySet()){
						if(n.color==-1){
							n.color = color;
							que.add(n);
						}
					}
				}
				color++;
			}
		}
		return color;
	}


}