#include <fstream>
#include <vector>
#define DIM 100005

using namespace std;

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

vector <int> L[DIM];

int v[DIM], n, cc, i, j, m, t;

void dfs(int nod) {
    int i, k;
    v[nod] = 1;
    for (i=0; i<L[nod].size(); i++){
        k = L[nod][i];
        if (v[k] == 0)
            dfs(k);
    }
}

int main () {
    fin >> n >> m;
    for (t=1; t<=m; t++) {
        fin >> i >> j;
        L[i].push_back(j);
        L[j].push_back(i);
    }
    for (i=1; i<=n; i++)
        if (v[i] == 0) {
            cc++;
            dfs(i);
        }
    fout << cc;
    return 0;
}