#include <cstdio>
#include <vector>
using namespace std;
vector < int > a[100005];
int n,m,cnt=0;
bool v[100005];

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

int main()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&n,&m);
	int x,y;
	for (int i=1;i<=m;++i)
	{
		scanf("%d%d",&x,&y);
		a[x].push_back(y);
		a[y].push_back(x);
	}
	for (int i=1;i<=n;++i)
		if (!v[i])
		{
			dfs(i);
			cnt++;
		}
	printf("%d\n",cnt);
	return 0;
}