#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

const int NLIMIT = 100005;

int N,M; // noduri si muchii
bool vizitat[NLIMIT];

vector <int> Muchii[NLIMIT];

int insule = 0;

void DFS(int Nod){
    vizitat[Nod] = true;
    for(unsigned int i = 0; i<Muchii[Nod].size();i++){
        int vecin = Muchii[Nod][i];
        if(!vizitat[vecin])
            DFS(vecin);
    }
}
void citire(){
    fin >> N >> M;
    for(int i=1;i<=M;i++){
        int x , y;
        fin >> x >> y;
        //legatura muchiilor
        Muchii[x].push_back(y);
        Muchii[y].push_back(x);
    }
    for(int i=1;i<=N;i++){
        if(!vizitat[i]){
            insule = insule + 1;
            DFS(i);
        }
    }
    fout << insule << "\n";
}
int main() {
    citire();
    return 0;
}