#include <bits/stdc++.h>

using namespace std;

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

int main() {
    int n, m, x, y;

    fin >> n >> m;

    vector<int> adj[n + 1];
    vector<int> visited(n + 1, 0);

    for (int i = 1; i <= m; i++) {
        fin >> x >> y;

        adj[x].push_back(y);
        adj[y].push_back(x);
    }

    int nr_of_components = 0;

    stack<int> s;

    for (int i = 1; i <= n; i++) {
        if (visited[i]) continue;

        s.push(i);
        nr_of_components++;

        while (!s.empty()) {
            int node = s.top();
            s.pop();

            visited[node] = 1;

            for (int neigh: adj[node]) {
                if (visited[neigh]) continue;

                s.push(neigh);
            }
        }

    }

    fout << nr_of_components;

    return 0;
}