//ALEX ENACHE

#include <vector>
#include <algorithm>
#include <queue>
#include <map>
#include <set>
#include <unordered_map>
#include <time.h>
#include <iomanip>
#include <deque>
#include <math.h>
#include <cmath>
#include <assert.h>
#include <stack>
#include <bitset>
#include <random>
#include <chrono>

using namespace std;

//#include <iostream>
#include <fstream>
ifstream cin ("dfs.in");ofstream cout ("dfs.out");

vector < int > gr[100100];
stack < int > q;
bool used[100100];

int main() {

    //freopen("input", "r", stdin);freopen("output", "w", stdout);

    ios::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cout << setprecision(10) << fixed;
    mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
    srand(time(NULL));

    //citesc datele
    int noduri , muchii;
    cin>>noduri>>muchii;

    //citesc muchiile
    for (int i=1; i<=muchii; i++){
        int x , y;
        cin>>x>>y;
        //trag muchie
        gr[x].push_back(y);
        gr[y].push_back(x);
    }

    int cont = 0;

    for (int sursa=1; sursa<=noduri; sursa++){
        if (used[sursa]){
            continue;
        }

        cont++;

        q.push(sursa);
        used[sursa] = true;

        //cat timp nu e goala coada
        while (!q.empty()){
            int nod = q.top();
            q.pop();
            for (int i=0; i<gr[nod].size(); i++){
                if (!used[gr[nod][i]]){
                    q.push(gr[nod][i]);
                    used[gr[nod][i]] = true;
                }
            }
        }
    }

    //afisez nr de componente conexe
    cout<<cont;

    return 0;
}