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

#define NMAX 100005

using namespace std;

int N, M, ans;
vector <int> g[NMAX];
bool used[NMAX];

void read() {
    int x, y;

    cin >> N >> M;

    for (int i = 1; i <= M; i++) {
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
}

void dfs(int root) {
    vector <int> :: iterator it;
    used[root] = true;

    for (it = g[root].begin(); it != g[root].end(); ++it) {
        if (!used[*it]) {
            dfs(*it);
        }
    }
}

int main() {
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);

    read();
    for (int i = 1; i <= N; ++i) {
        if (!used[i]) {
            dfs(i);
            ans++;
        }
    }
    cout << ans;
}