/*
 * dfs.cpp
 *
 *  Created on: Jun 23, 2017
 *      Author: andreir
 */

#include <fstream>
#include <vector>
using namespace std;

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

bool Vizitat[100005];
int N, M;

vector<int> D[100005];

void Read() {
    int x, y;
    in >> N >> M;
    for (int i = 1; i <= M; i++) {
        in >> x >> y;
        D[x].push_back(y);
        D[y].push_back(x);
    }
}

void dfs(int nod) {
    int vecin;
    Vizitat[nod] = 1;
    for (int i = 0; i < (int) D[nod].size(); i++){
        vecin = D[nod][i];
        if (Vizitat[vecin] == 0)
            dfs(vecin);
    }
}

int main() {
    int k = 0;
    Read();
    for (int i = 1; i <= N; i++) {
        if (Vizitat[i] == 0) {
            dfs(i);
            k++;
        }
    }
    out << k;
    return 0;
}