#include <fstream>
#include <vector>
#define NMAX 100004

using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

vector<int> V[NMAX];

int N,M,Cont;
bool Viz[NMAX];

void DF(int nod)
{
	Viz[nod] = 1;
	for(int i=0;i<V[nod].size();i++)
		if(!Viz[V[nod][i]])
			DF(V[nod][i]);
}

int main ()
{
	int x,i,y;
	in>>N>>M;
	while(M--)
	{
		in>>x>>y;
		V[x].push_back(y);
		V[y].push_back(x);
	}
	for(i=1;i<=N;i++)
		if(!Viz[i])Cont++,DF(i);
	out<<Cont<<'\n';
	return 0;
}