#include<stdio.h>
#include<vector>

using namespace std;


vector<int> a[100002];
bool viz[100002];


void backt(int x)
{
	int i,n=a[x].size();
	for(i=0;i<n;++i)
		if(!viz[a[x][i]])
		{
			viz[a[x][i]]=1;
			backt(a[x][i]);
		}
}




int main()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	int n,m,i,x,y,nr=0;
	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(!viz[i])
		{
			++nr;
			backt(i);
		}
	printf("%d\n",nr);
	return 0;
}