#include <stdio.h>
#include<vector>
#include<iostream>
using namespace std;

int n, m, cnt = 0;
vector<int> v[100005];
vector<bool> viz(100005);

void citire()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d %d",&n,&m);
	int i, x, y;

	for (i = 1; i <= m; i++)
	{
		scanf("%d %d",&x,&y);
		v[x].push_back(y);
		v[y].push_back(x);
	}
}

void dfs(int nod)
{
	viz[nod] = 1;

	for(int i = 0; i < v[nod].size(); ++i)
		if(viz[v[nod][i]] == 0)
			dfs(v[nod][i]);
}


int main()
{
	citire();
	int i;
	for(int i = 1; i <= n; ++i)
		if(!viz[i])
		{
			cnt++;
			dfs(i);
		}
	printf("%d\n", cnt);

	return 0;
}