#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

vector<int> adiacenta[100015];
bool vizitat[100010] = {false};

int varfuri, muchii, conexe;

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


int citire() {
	int from, to;
	fin >> varfuri >> muchii;
	for (int i = 0; i < muchii; i++) {
		fin >> from >> to;
		adiacenta[from].push_back(to);
		adiacenta[to].push_back(from); //graful e neorientat
	}
	return 0;
}

int df(int inceput) {
	vizitat[inceput] = true;
	for(int& varf : adiacenta[inceput]) {
		if (!vizitat[varf])
			df(varf);
	}

/*	int size = adiacenta[inceput].size(), varf;
	for (int i = 0; i < size; ++i) {
		varf = adiacenta[inceput][i];
		if (!vizitat[varf])
			df(varf);
	}*/
	return 0;
}


int main(int argc, char const *argv[]) {
	int componente = 0;
	citire();
/*
	for (int i = 0; i < varfuri; i++) {
		vizitat[i] = false;
	}*/
	for (int varf = 0; varf < varfuri; varf++) {
		if (!vizitat[varf]) {
			df(varf);
			componente++;
		}
	}
	fout << componente;
	return 0;

}