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

std::ifstream f("DFS.in");
std::ofstream g("DFS.out");

std::vector<std::vector<int>> adj;
std::vector<int> viz;

void DFS(int i) {
    viz[i] = 1;
    for (int j : adj[i]) {
        if (viz[j] == 0)
            DFS(j);
    }

}

int main() {
    int n,m,cnt=0;

    f >> n >> m;

    adj.resize(n+5);
    viz.resize(n+5);

    for (int i = 0; i < m; i++) {
        int x,y;
        f >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    for (int i = 1; i <= n; i++) {
        if (viz[i] == 0) {
            DFS(i);
            cnt++;
        }
    }
    g << cnt;

    return 0;
}