#include <fstream>
#include <vector>

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

const int NMAX = 100005;

vector < vector < int > > lista(NMAX);
bool vizitat[NMAX]; int N, M;

void DFS(int nod)
{
    vizitat[nod] = true;
    for(unsigned int i = 0; i < lista[nod].size(); i++)
    {
        int vecin = lista[nod][i];
        if(!vizitat[vecin])
            DFS(vecin);
    }
}

int componente_conexe()
{
    int count = 0;
    for(int i = 1; i <= N; i++)
        if(!vizitat[i])
        {
            DFS(i);
            count++;
        }
    return count;
}

int main()
{
    fin >> N >> M; int x, y;
    while(fin >> x >> y)
    {
        lista[x].push_back(y);
        lista[y].push_back(x);
    }
    fout << componente_conexe();
    
    fin.close();
    fout.close();
    return 0;
}