//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];
bool used[100100];

void dfs(int nod){
    used[nod] = true;
    for (auto x : gr[nod]){
        //x = gr[nod][i]
        if (!used[x]){
            dfs(x);
        }
    }
}

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++;

        dfs(sursa);
    }

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

    return 0;
}