#include <fstream>
#include <vector>
#include <bitset>

using namespace std;

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

const int N = 100010;

int n, m, x, y, ct;
vector<int> a[N];
bitset<N> viz;

void dfs(int);

int main() {
    fin >> n >> m;
    for (; m != 0; m--) {
        fin >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for (int i = 1; i <= n; i++)
        if (!viz[i]) {
            viz[i] = 1;
            dfs(i);
            ct++;
        }

    fout << ct;
    return 0;


}

void dfs(int nod) {
    for (auto it:a[nod])
        if (!viz[it]) {
            viz[it] = 1;
            dfs(it);
        }
}