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

const int NMAX = 100010;
vector <int> vecini[NMAX];
bool vizitat[NMAX];

void dfs(int nod)
{
    vizitat[nod] = 1;
    for (auto i:vecini[nod]) {
        if (vizitat[i] == 0) 
            dfs(i);
    }
}

int main()
{
    ifstream in("dfs.in");
    ofstream out("dfs.out");

    int n, m, ans = 0;
    in >> n >> m;
    for (int i = 0; i < m; i++) {
        int a, b;
        in >> a >> b;
        vecini[a].push_back(b);
        vecini[b].push_back(a);
    }

    for (int i = 1; i <= n; i++) {
        if (vizitat[i] == 0) {
            dfs(i);
            ans += 1;
        }
    }
    out << ans << '\n';
    return 0;
}