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

using namespace std;

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

constexpr int NMAX = 100000;
constexpr int MMAX = 200000;

std::vector<std::vector<int>> liste_de_adiacenta;
std::bitset<NMAX> vazut;
int n, m;

int citire(ifstream& fisier, std::vector<std::vector<int>>& vectorul) {
    if (!(fisier >> n >> m))
        return 1;
        
    if (n > NMAX || m > MMAX)
        return 1;
    
    vectorul.resize(n + 1);
    for (int i = 0; i < m; ++i) {
        int x, y;
        fisier >> x >> y;
        vectorul[x].push_back(y);
        vectorul[y].push_back(x);
    }
    return 0;
}

void dfs(int numar, const std::vector<std::vector<int>>& vectorul, std::bitset<NMAX>& bitsetul) {
    bitsetul.set(numar);
    for (auto x : vectorul[numar]) {
        if (!bitsetul.test(x)) {
            dfs(x, vectorul, bitsetul);
        }
    }
}

void numaraComponenteConexe(ofstream& fisier, const std::vector<std::vector<int>>& vectorul, std::bitset<NMAX>& bitsetul) {
    int contor = 0;
    for (int i = 1; i <= n; ++i) {
        if (!bitsetul.test(i)) {
            contor++;
            dfs(i, vectorul, bitsetul);
        }
    }
    fisier << contor << "\n";
}

int main() {
    if (citire(f, liste_de_adiacenta) == 0) {
        numaraComponenteConexe(g, liste_de_adiacenta, vazut);
    }
    return 0;
}