#include <fstream>
#include <vector>

using namespace std;

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

const int NMAX = 100010;
const int MMAX = 200010;

int N, M;
vector<int> G[NMAX];

int viz[NMAX];
void DFS (int nod) {
    viz[nod] = 1;

    for (auto &it : G[nod]) {
        if ( !viz[it]) {
            DFS (it);
        }
    }
}

int main () {
    fin >> N >> M;
    for (int i = 1; i <= M; i++) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    int ANS = 0;
    for (int i = 1; i <= N; i++) {
        if ( !viz[i]) {
            ANS ++;
            DFS (i);
        }
    }
    fout << ANS << '\n';

    return 0;
}