#include<cstdio>
#include<vector>
using namespace std;

int n,m,i,j,x,y,nr,viz[100001];
vector <int> G[100001];

int dfs(int nod)
{
	int i;
	if(viz[nod])
		return 0;
	viz[nod]=nr;
	for(i=0;i<G[nod].size();i++)
		dfs(G[nod][i]);
	return 0;
}

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(viz[i]==0)
		{
			nr++;
			dfs(i);
		}
	printf("%d",nr);
	return 0;
}