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

using namespace std;

class Graf {
    vector<list<int>> noduri;
    void dfs(int nod, vector<bool> &vizitate) {
        vizitate[nod] = true;
        for(auto i: noduri[nod])
            if(!vizitate[i])
                dfs(i, vizitate);
    }
public:
    Graf(vector<list<int>> _noduri) : noduri(_noduri) {}
    friend ostream& operator<< (ostream& os, Graf graf) {
        os << graf.noduri.size() << " nodes\n";
        for(int i = 0; i < graf.noduri.size(); i++) {
            os << "node " << i << ": ";
            for(int j: graf.noduri[i])
                os << j << " ";
            os << "\n";
        }
        return os;
    }

    int nrConexe() {
        vector<bool> vizitate(noduri.size());
        int nr = 0;
        for(int i = 0; i < noduri.size(); i++)
            if(!vizitate[i]) {
                nr++;
                dfs(i, vizitate);
            }
        return nr;
    }
};

int main() {
    ifstream in("file");
    ofstream out("dfs.out");
    int noduri, muchii;
    in >> noduri >> muchii;
    vector<list<int>> aux(noduri);
    for(int i = 0; i < muchii; i++) {
        int x1, x2;
        in >> x1 >> x2;
        aux[x1 - 1].push_back(x1 - 1);
        aux[x2 - 1].push_back(x2 - 1);  // daca e neorientat
    }
    Graf graf(aux);
    out << graf.nrConexe();
    return 0;
}