#include<iostream>
#include<cstdio>
#include<vector>
using namespace std;
#define maxn 100005
vector <int> a[maxn];
int n,m,i,x,y,v[maxn],k;

void dfs(int nod)
{
	int i;
	v[nod]++;
	for(i=0;i<a[nod].size();++i)
		if(!v[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(!v[i])
		{
			k++;
			dfs(i);
		}
	printf("%d\n",k);
	return 0;
}