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

int n, m;
vector<vector<int>> adj;
vector<int> visited;

void dfs(int start)
{
    stack<int> s;

    s.push(start);
    visited[start] = true;

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

        for (int next : adj[node]) {
            if (!visited[next]) {
                s.push(next);
                visited[next] = true;
            }
        }
    }
}

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

    cin >> n >> m;
    adj.resize(n);
    visited.resize(n, false);

    for (int i = 0; i < m; i++) {
        int u, v;
        cin >> u >> v;
        u--;
        v--;

        adj[u].push_back(v);
        adj[v].push_back(u);
    }

    int ans = 0;
    for (int i = 0; i < n; i++) {
        if (!visited[i]) {
            dfs(i);
            ans++;
        }
    }

    cout << ans << '\n';

    return 0;
}