#include <bits/stdc++.h>

using namespace std;

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

vector<int> viz;
vector<vector<int>> gr;

void bfs(int start) {
    queue<int> q;
    viz[start] = 1;
    q.push(start);

    while (q.size() != 0) {
        int node = q.front();
        q.pop();

        for (auto &x : gr[node]) {
            if (!viz[x]) {
                viz[x] = 1;
                q.push(x);
            }
        }
    }
}

int main() {
    int n, m;
    fin >> n >> m;

    viz = vector<int>(n + 1);
    gr = vector<vector<int>>(n + 1);

    for (int i = 0; i < m; i++) {
        int u, v;
        fin >> u >> v;
        gr[u].push_back(v);
        gr[v].push_back(u);
    }

    int cnt = 0;
    for (int i = 1; i <= n; i++) {
        if (!viz[i]) {
            bfs(i);
            cnt++;
        }
    }

    fout << cnt << '\n';
    return 0;
}