#include <bits/stdc++.h>
using namespace std;

class Task { // T = O(n + m) 
 public:
    void solve() {
        read_input();
        print_output(get_result());
    }
 
 private:
    static constexpr int NMAX = (int)1e5 + 5;
    int n, m;

    vector<int> adj[NMAX];

    void read_input() {
        ifstream fin("dfs.in");
        fin >> n >> m;
        for (int i = 1, x, y; i <= m; i++) {
            fin >> x >> y; // muchie (x, y)
            adj[x].push_back(y);
            adj[y].push_back(x);
        }
        fin.close();
    }

    int get_result() {
        vector<bool> used(n + 1, false);
        int count = 0;

        for (int node = 1; node <= n; ++node) {
            if (!used[node]) {
                dfs(node, used);
                count++;
            }
        }

        return count;
    }

    void dfs(int node, vector<bool>& used) {
        used[node] = true;

        // parcurg vecinii
        for (auto& neigh : adj[node]) {
            if (!used[neigh]) {
                dfs(neigh, used);
            }
        }
    }

    void print_output(int result) {
        ofstream fout("dfs.out");
        fout << result << "\n";
        fout.close();
    }
};


int main() {
    auto* task = new (nothrow) Task();

    if (!task) {
        cerr << "new failed!\n";
        return -1;
    }

    task->solve();
    delete task;

    return 0;
}