#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100001;

int n, m;
bool viz[N];
vector <int> a[N];

void citire() {
    in >> n >> m;
    int x, y;

    for (int i = 0; i < m; i++) {
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

    in.close();
}

void dfs(int x) {
    viz[x] = true;

    for (int i = 0; i < a[x].size(); i++) {
        if (!viz[a[x][i]]) {
            dfs(a[x][i]);
        }
    }
}

int main()
{
    int nr = 0;
    citire();
    for (int i = 1; i <= n; i++) {
        if (!viz[i]) {
            dfs(i);
            nr++;
        }
    }
    out << nr;
    out.close();
}