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

using namespace std;

void DFS(int i, vector<int> &viz, vector<vector<int> > &L) {
    viz[i] = 1;
    for (auto vecin: L[i]) {
        if (viz[vecin] == 0) {
            DFS(vecin, viz, L);
        }
    }
}

int main() {
    ifstream f("dfs.in");
    ofstream g("dfs.out");

    int n, m, x, y, comp_conexe = 0;
    f >> n >> m;
    vector<vector<int> > L(n + 1);
    vector<int> d(L.size(), -1), viz(n + 1, 0), tata(n + 1, 0);
    for (int i = 0; i < m; i++) {
        f >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) {
        if (viz[i] == 0) {
            DFS(i, viz, L);
            comp_conexe++;
        }
    }
    g << comp_conexe;
    return 0;
}