#include <fstream>

#include <vector>

using namespace std;

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

const int NMAX = 100005;

int n, m, sol;
vector <int> gr[NMAX];
bool vf[NMAX];

void DFS(int nod) {
    vf[nod] = true;
    for (int i = 0; i < gr[nod].size(); i++) {
        if (!vf[gr[nod][i]])
            DFS(gr[nod][i]);
    }
}


int main() {
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int x, y;
        fin >> x >> y;
        gr[x].push_back(y);
        gr[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) {
        if (!vf[i]) {
            sol++;
            DFS(i);
        }
    }
    fout << sol;
    return 0;
}