#include <bits/stdc++.h>
using namespace std;

class Task {
public:
    void solve() {
        read_input();
        print_output(get_result());
    }

private:
    // numarul maxim de noduri
    static constexpr int NMAX = (int)1e5 + 5; // 10^5 + 5 = 100.005

    // n = numar de noduri, m = numar de muchii/arce
    int n, m;

    // adj[node] = lista de adiacenta a nodului node
    // exemplu: daca adj[node] = {..., neigh, ...} => exista muchia (node, neigh)
    vector<int> adj[NMAX];

    // nodul sursa in parcurgerea BFS

    void read_input() {
        ifstream fin("dfs.in");
        fin >> n >> m;
        for (int i = 1, x, y; i <= m; i++) {
            fin >> x >> y; // muchie (x, y)
            adj[x].push_back(y);
            adj[y].push_back(x);
        }
        fin.close();
    }

    void dfs(int node, vector<char>&d){
        d[node] = 1;
        for(auto neigh: adj[node]){
            if(!d[neigh]){
                dfs(neigh, d);
            }
        }
    }

    int get_result() {

        vector<char> d(n + 1);

        for(int node = 1; node <= n; node++)
            d[node] = 0;


        int k = 0;

        for(int i = 1; i <=n; i++){
            if(d[i] == 0){
                k++;
                dfs(i, d);
            }
        }
        return k;
    }



    void print_output(const int k) {
        ofstream fout("dfs.out");
        fout<<k<<'\n';
        fout.close();
    }
};

// [ATENTIE] NU modifica functia main!
int main() {
    // * se aloca un obiect Task pe heap
    // (se presupune ca e prea mare pentru a fi alocat pe stiva)
    // * se apeleaza metoda solve()
    // (citire, rezolvare, printare)
    // * se distruge obiectul si se elibereaza memoria
    auto* task = new (nothrow) Task(); // hint: cppreference/nothrow
    if (!task) {
        cerr << "new failed: WTF are you doing? Throw your PC!\n";
        return -1;
    }
    task->solve();
    delete task;
    return 0;
}