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

int n,m,a,b,i,x,cmp,viz[100005];
vector<int> v[100005];

void read(),solve(),dfs(int x);

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])
		{
			cmp++;
			dfs(i);
		}
	printf("%d",cmp);
}

void dfs(int x)
{
	vector <int>::iterator it;
	viz[x]=1;
	for(it=v[x].begin();it!=v[x].end();it++)
		if(!viz[*it])
			dfs(*it);
}