const int N = 100100;
vector <vector <int>> g(N);
bool used[N];

void dfs(int v) {
    used[v] = true;
    for (int i = 0; i < g[v].size(); ++i) {
        int u = g[v][i];
        if (!used[u]) {
            dfs(u);
        }
    }
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n, m; cin >> n >> m;
    for (int i = 0; i < m; ++i) {
        int u1, u2; cin >> u1 >> u2;
        g[u1].push_back(u2);
        g[u2].push_back(u1);
    }
    int connect = 0;
    for (int i = 1; i <= n; ++i) {
        if (!used[i]) {
            dfs(i);
            connect++;
        }
    }
    cout << connect << '\n';
}