#include<stdio.h>
#include<vector>
using namespace std;
vector <int> a[100001];
int v[100001],n;
void dfs(int nod)
{
	int i;
	for(i=0;i<a[nod].size();i++)
		if(v[a[nod][i]]==0)
		{
			v[a[nod][i]]=1;
			dfs(a[nod][i]);
		}
}
int main()
{
	int i,m,x,y,nr=0;
	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);
		a[x].push_back(y);
		a[y].push_back(x);
	}
	for(i=1;i<=n;i++)
	{
		if(v[i]==0)
		{
			dfs(i);
			nr++;
		}
	}
	printf("%d",nr);
	return 0;
}