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

vector<int> g[100001];
bool viz[100001];
void BFS (int a) {
    queue<int> q;
    q.push(a);
    viz[a] = true;
    while (!q.empty()) {
        int nod = q.front();
        q.pop();
        for (auto i: g[nod]) {
            if(viz[i] == false) {
                q.push(i);
                viz[i] = true;
            }
        }

    }
}


int main() {
    ifstream cin ("dfs.in");
    ofstream cout ("dfs.out");
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; ++i) {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    int cnt = 0;
    for (int i = 1; i <= n; ++i) {
        if (viz[i] == false) {
            BFS(i);
            ++cnt;
        }
    }
    cout << cnt;
    return 0;
}