#include <iostream>
#include <cstdio>
#include <algorithm>
#include <vector>
#include <string>

using namespace std;

#define NM 100005
#define PB push_back

vector <int> G[NM];
int N, M, viz[NM], ans;

void dfs(int nod)
{
	viz[nod] = 1;
	for (int i = 0; i < G[nod].size(); ++i)
	{
		int nnod = G[nod][i];
		if (viz[nnod]) continue;
		dfs(nnod);
	}	
}

int main()
{
	freopen ("dfs.in", "r", stdin);
	freopen ("dfs.out", "w", stdout);
	
	scanf ("%d %d", &N, &M);
	
	for (int i = 1; i <= M; ++i)
	{
		int a, b;
		scanf ("%d %d", &a, &b);
		G[a].PB(b);
		G[b].PB(a);
	}	
	
	for (int i = 1; i <= N; ++i) if (!viz[i]) {dfs(i); ++ans;}
	
	printf ("%d\n", ans);
	
	return 0;
}