#include<stdio.h>
#include<vector>

using namespace std;

int N, M, result = 0;
int visited[100002] = {0};
vector<int> v[100002];

void DFS(int index)
{
	int j;
	visited[index] = 1;
	for (j=0; j<v[index].size(); j++)
		if (visited[v[index][j]] == 0)
			DFS(v[index][j]);
}

int main(){
	int x, y, i;
	
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);

	scanf("%d %d ", &N, &M);
	
	for (i = 0; i < M ; i++){
		scanf("%d %d",&x,&y);
		v[x].push_back(y);
		v[y].push_back(x);
	}

	for (i = 1; i <= N; i ++){
		if(visited[i] == 0){
			result ++;
			DFS(i);
		}
	}

	printf("%d ", result);
	
	return 0;
}