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

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

int n, m, insule;
bool vizitat[100005];
vector < int > v[100005];

void DFS(int nod) {
    vizitat[nod] = true;
    for (unsigned int i = 0 ; i < v[nod].size(); i++) {
        int vecin = v[nod][i];
        if (!vizitat[vecin]) {
            DFS(vecin);
        }
    }
}

void citire() {
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) {
        if (!vizitat[i]) {
            insule++;
            DFS(i);
        }
    }
}

int main() {
    citire();
    fout << insule;
    return 0;
}