#include <iostream>
#include <cstdio>
#include <vector>
#include <stack>
#include <queue>
#include <algorithm>
#include <fstream>
using namespace std;
#define inf 0xfffffff
#define MOD 1999999973

vector<int> gr[100010];
bool viz[100010];
int n, m, nr;

void dfs(int x) {
	viz[x] = 1;
	for (int i = 0; i < gr[x].size(); i++)
	if (!viz[gr[x][i]]) {
		dfs(gr[x][i]);
	}
}

int main() {
	int s, x, y;
	
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	
	scanf("%d %d %d", &n, &m);
	for (int i = 1; i <= m; i++) {
		scanf("%d %d", &x, &y);
		gr[x].push_back(y);
		gr[y].push_back(x);
	}
	for (int i = 1; i <= n; i++)
		if (!viz[i]) {
			nr++;
			dfs(i);
		}
		
	printf("%d\n", nr);

	return 0;
}