#include <bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int NLIM = 100005;

int N,M,insule=0;
bool vizitat[NLIM];

vector <int> Muchii[NLIM];

void DFS(int Nod){
	vizitat[Nod] = true;
	for(unsigned int i=0; i< Muchii[Nod].size();i++){
		int Vecin = Muchii[Nod][i];
		if(!vizitat[Vecin]) DFS(Vecin);
	}
}
void citire(){
	fin >> N >> M;
	for(int i=1; i<=M; i++){
		int x,y;
		fin >> x >> y;
		Muchii[x].push_back(y);
		Muchii[y].push_back(x);
	}
	for(int i=1;i<=N;i++){
		if(!vizitat[i]){
			insule += 1;
			DFS(i);
		}
	}
}
int main(){
	citire();
	fout << insule << "\n";
	fin.close();
	fout.close();
return 0;
}