#include <iostream>
#include <fstream>

using namespace std;

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

const int max_val = 100001;

struct nod
{
    int info;
    nod * urm;
}* lista[max_val];

int n, vizitat[max_val];

void adaugare (int x, int y)
{
    nod * t = new nod;
    t -> info = y;
    t -> urm = lista[x];
    lista[x] = t;
}

void dfs (int x)
{
    vizitat[x] = 1;
    nod * t = lista[x];
    while (t)
    {
        if (vizitat[t -> info] == 0)
            dfs(t -> info);
        t = t -> urm;
    }
}

int main()
{
    int m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        adaugare (x, y);
        adaugare (y, x);
    }
    int comp_conexe = 0;
    for (int i = 1; i <= n; i++)
    {
        if (vizitat[i] == 0)
        {
            comp_conexe++;
            dfs(i);
        }
    }
    fout << comp_conexe;
    return 0;
}