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

using namespace std;

const int nMax = 100005;

//int n, m, nrComp;

class Graf {
private:
    int m_n, m_m;
    list<int> listAd[nMax];

    // DFS
    bool dfsViz[nMax] = {};
public:
    explicit Graf(int n = 0, int m = 0) : m_n(n), m_m(m) {}

    void neorientatCitesteListaAdiacenta(ifstream &in) {
        for (int i = 0; i < m_m; i++) {
            int x, y;
            in >> x >> y;
            listAd[x].push_back(y);
            listAd[y].push_back(x);
        }
    }

    void neorientatDFS(int k) {
        dfsViz[k] = true;

        for (auto x: listAd[k]) {
            if (!dfsViz[x]) {
                neorientatDFS(x);
            }
        }
    }

    int neorientatNrCompConexe() {
        int nrComp = 0;
        for (int i = 1; i <= m_n; i++) {
            if (!dfsViz[i]) {
                nrComp++;
                neorientatDFS(i);
            }
        }
        return nrComp;
    }
};

int main() {
    // Input rapid
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    // Input
    ifstream in("dfs.in");
    ofstream out("dfs.out");
    int n, m;
    in >> n >> m;

    Graf g(n, m);
    g.neorientatCitesteListaAdiacenta(in);
    out << g.neorientatNrCompConexe();

    in.close();
    out.close();

    return 0;
}