#include <cstdio>
#include <vector>
using namespace std;
#define nmax 100010

int viz[nmax], cont, n, m;
vector <int> v[nmax];

void dfs(int nod)
{
	viz[nod]=1;
	vector<int>::iterator it;
	for (it=v[nod].begin(); it!=v[nod].end(); it++)
		if (!viz[*it])  dfs(*it);
}

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