#include <iostream>
#include <string>
#include <vector>

using namespace std;

#define NM 100005

int N, M;

vector <int> G[NM];

bool viz[NM];

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

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