#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <fstream>
using namespace std;

const int NMAX = 100000; // nr maxim din restrictii

vector<int> adj[NMAX + 1]; // lista de adiacenta
vector<bool> visited;
int N;
int M;

int compConex = 0;

void readInput() {
    ifstream f("dfs.in");
    f >> N >> M;
    for (int i = 1; i <= M; i++) {
        int u, v;
        f >> u >> v;
        adj[u].push_back(v); // orientat
        adj[v].push_back(u); // neorientat
    }
    f.close();
    // alte inputuri din porblema
    visited = vector(N + 1, false);
}

// alte functii pentru rezolvarea problemei

void dfs(int start) {
    visited[start] = true;
    for (auto j : adj[start]) {
        if (visited[j] == false) {
            visited[j] = true;
            dfs(j);
        }
    }
}

void output() {
    // afisare rezultate
    ofstream g("dfs.out");
    g << compConex;
    g.close();
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    readInput();
    for (int i = 1; i <= N; i++) {
        if (visited[i] == false) {
            dfs(i);
            compConex ++;
        }
    }
    output();
    return 0;
}