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

using namespace std;

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

const int NMAX=100005;

int N,M;

bool vizitat[NMAX];

vector < int > Muchii[NMAX];

int conexe=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;
    Muchii[x].push_back(y);
    Muchii[y].push_back(x);
}
for (int i=1; i<=N; i++)
    {
    if (!vizitat[i]) {
        conexe+=1;
        DFS(i);
    }
    }
    }
int main() {
citire();
fout<<conexe<< "\n";
return 0;
}