#include<cstdio>
#include<vector>
#define N 100100
using namespace std;
vector<int> v[N];
int n,m,a,b,i,c,viz[N];
void read(), solve(),DFS(int nod);
int main()
{
	read();
	solve();
	return 0;
}
void read()
{
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	scanf("%d%d",&n,&m);
	for(;m;m--)
	{
		scanf("%d%d",&a,&b);
		v[a].push_back(b);
		v[b].push_back(a);
	}
}
void solve()
{
	for(i=1;i<=n;i++)
		if(!viz[i])
		{
			c++;
			DFS(i);
		}
		printf("%d\n",c);
}
void DFS(int nod)
{
	vector<int>::iterator it;
	viz[nod]=1;
	for(it=v[nod].begin();it!=v[nod].end();it++)
		if(!viz[*it])
			DFS(*it);
}