using namespace std;
#include<fstream>
#include<vector>
# define Nmax 100002
ifstream eu("dfs.in");
ofstream tu("dfs.out");
vector <int>G[Nmax];
bool use[Nmax];
int N,M,Nc;
void DFS(int nod)
{
	vector <int>:: iterator it;
	use[nod]=1;
	for(it=G[nod].begin();it!=G[nod].end();it++)
	{
		if(!use[*it])
			DFS(*it);
	}
}
void Read()
{
	int x,y;
	eu>>N>>M;
	for(int i=1;i<=M;i++)
	{
		eu>>x>>y;
		G[x].push_back(y);
		G[y].push_back(x);
	}
}
int main()
{
	Read();
	for(int i=1;i<=N;i++)
		if(!use[i])
		{
			DFS(i);
			Nc++;
		}
	tu<<Nc;	
	return 0;
}