#include<stdio.h>
#include<vector>
using namespace std;
int n,m,num,u[100005],i,x,y;
vector<int> a[100005];

void dfs(int nod)
{
	u[nod]=1;
	int i;
	for(i=0;i<a[nod].size();i++)
		if(!u[a[nod][i]])
			dfs(a[nod][i]);
}

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);
		a[x].push_back(y);
		a[y].push_back(x);
	}
	for(i=1;i<=n;i++)
		if(!u[i])
		{
			num++;
			dfs(i);
		}
	printf("%d\n",num);
	return 0;
}