#include<fstream>
#include<vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int N=100010;
vector<int>a[N];
int n,m;
bool viz[N];
void read()
{
	int x,y;
	in>>n>>m;
	for(int i=1;i<=m;i++)
	{
		in>>x>>y;
		a[x].push_back(y);
		a[y].push_back(x);
	}
}
void dfs(int x)
{
	viz[x]=1;
	for(int i=0;i<a[x].size();i++)
		if(!viz[a[x][i]])
			dfs(a[x][i]);
}
int main()
{
	int c=0;
	for(int i=1;i<=n;i++)
		if(!viz[i])
		{
			dfs(i);
			c++;
		}
	out<<c;
	return 0;
}