#include <fstream>
#include <vector>

using namespace std;

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

#define NMAX 100005

int n, m;
bool viz[NMAX];
vector<int> G[NMAX];

void citire() {
    f >> n >> m;
    int x, y;
    for (int i = 1; i <= m; i++) {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void dfs(int x) {
    viz[x] = true;
    for (auto &nod: G[x])
        if (!viz[nod])
            dfs(nod);
}

void parcurgere() {
    int nrc = 0;
    for (int i = 1; i <= n; ++i)
        if (!viz[i]) {
            nrc++;
            dfs(i);
        }
    g << nrc;
}

int main() {
    citire();
    parcurgere();
    return 0;
}