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

int n,m,s,ap[100100],sol;
queue<int> Q;
vector<int> A[100100];

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

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