#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n,m,x,y,cc,v[100010];
vector<int> L[100010];
void dfs(int nod) {
	v[nod]=1;
	for (int i=0;i<L[nod].size();i++) {
		int vecin=L[nod][i];
		if (v[vecin]==0)
			dfs(vecin);
	}
}
int main() {
	fin>>n>>m;
	while (m--) {
		fin>>x>>y;
		L[x].push_back(y);
		L[y].push_back(x);
	}
	for (int i=1;i<=n;i++) {
		if (v[i]==0) {
			cc++; dfs(i);
		}
	}
	fout<<cc;
	return 0;
}