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

int n,m,s,v[100100],s;
vector<int> w[100100];

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

int main()
{
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	
	in>>n>>m;
	for(int i=1;i<=m;++i)
	{
		int x,y;
		in>>x>>y;
		w[x].push_back(y);
		w[y].push_back(x);
	}
	
	for(int i=1;i<=n;++i)
	{
		if(!v[i])
		{
			dfs(i);
			++s;
		}
	}
	
	g<<s<<'\n';
	
	g.close();
	return 0;
}