#include <cstdio>
#include <vector>
using namespace std;
int sel[100100],m,n,x,y,nr,i;
vector <int> g[100100];
vector <int>::iterator it;
void df(int x)
{
	//int i;
	vector <int>::iterator it;
	sel[x]=1;
	for (it=g[x].begin();it!=g[x].end();it++)
		if (sel[*it]==0)
		{
			df(*it);
		}
}
int main()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&n,&m);
	for (i=1;i<=m;i++)
	{
	    scanf("%d%d",&x,&y);
		g[x].push_back(y);
		g[y].push_back(x);
	}
	for (i=1;i<=n;i++)
		if (sel[i]==0) 
		{
			nr++;
			sel[i]=1;
			df(i);
		}
	printf("%d",nr);
	return 0;
}