#include<fstream>
using namespace std;
int n,m,nr=0,viz[100005];
//ifstream f("frumoasa.in");
//ofstream g("frumoasa.out");
ifstream f("dfs.in");
ofstream g("dfs.out");
typedef struct nod
{
    int x;
    nod *a;

}*pnod;
pnod v[100005];
void add(pnod &dist,int info)
{
    pnod p;
    p=new nod;
    p->x=info;
    p->a=dist;
    dist=p;
}
void citire()
{
    int x,y,i;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        add(v[x],y);
        add(v[y],x);

    }

}
void dfs(int nod)
{
    pnod p;
    viz[nod]=1;
    for(p=v[nod];p!=NULL;p=p->a)
    if(!viz[p->x])
    dfs(p->x);
}
int main()
{
    citire();
    int i;
    for(i=1;i<=n;i++)
    {
        if(!viz[i])
        {

            nr++;
            dfs(i);
        }
    }
    g<<nr<<endl;
    return 0;
}