#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
vector <int> v[100005];
int N, M, conexe, viz[100005];

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

    for (int i = 0; i < v[Nod].size(); i++) {
        int vecin = v[Nod][i];

        if(!viz[vecin])
            DFS(vecin);
    }
}

int main() {
    in >> N >> M;
    int x, y;
    for (int i = 0; i < M; i++) {
        in >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (int i = 1; i <= N; i++) {
        if(!viz[i]) {
            conexe++;
            DFS(i);
        }
    }

    out << conexe;

}