#include <iostream>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
struct nod
{
    int inf;
    nod *urm;
}*l[100005];
int n,m;
int u[100005];
void adaugnod(nod *&p,int x)
    {
        nod *c;
        c=new nod;
        c->inf=x;
        c->urm=p;
        p=c;
    }
void citire()
{
    int i;
    int x,y;
    f>>n>>m;
    for (i=1;i<=m;i++)
        {
            f>>x>>y;
            adaugnod(l[x],y);
            adaugnod(l[y],x);

        }

}
void df(int inf)
{
    nod *p;
    u[inf]=1;
    for (p=l[inf];p!=NULL;p=p->urm)
        {
            if (!u[p->inf])
                df(p->inf);
        }
}

int main()
{
    citire();
    int nr=0,i;

    for (i=1;i<=n;i++)
        {
            if (!u[i])

                   {
                      nr++;
                      df(i);
                   }


        }

    g<<nr;
    return 0;
}