#include <fstream>
#include <vector>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int LIM = 100005;
int n, m;
vector < int > muchii[LIM];
void citire() {
    fin >> n >> m;
    int x, y;
    for (int i = 1; i <= m; ++i) {
        fin >> x >> y;
        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
}

int vizitat[LIM];
void dfs(int nod) {
    vizitat[nod] = 1;
    int vecin;
    for (int i = 0; i < muchii[nod].size(); ++i) {
        vecin = muchii[nod][i];
        if (vizitat[vecin] == 0)
            dfs(vecin);
    }
}

int comp_conexe;
void parcurgere() {
    for (int i = 1; i <= n; ++i) {
        if (vizitat[i] == 0) {
            ++comp_conexe;
            dfs(i);
        }
    }
    fout << comp_conexe;
}

int main() {
    citire();
    parcurgere();
}