#include <iostream.h>
#include <fstream.h>
ifstream f("pairs.in");
ofstream g("pairs.out");
long z,j,k,kk,l,ll,n,i,c,x,y;
long m[1000],v[1000],w[1000];
void main()
{
 j=0;
 l=0;
 ll=0;
 f>>n;
 for (i=0;i<=n;i++)
 f>>m[i];
 for (i=0;i<=n;i++)
 {
   for (j=i+1;j<=n;j++)
   while (m[i]!=m[j] && m[i]!=0 && m[j]!=0){
   x=m[i]; y=m[j];
   while (m[i]!=1)
   {
    for (k=2;k<=m[i];k++)
    if (m[i]%k==0)
    {
     v[l]=k;
     l++;
     m[i]=m[i]/k;
    }
   }
   while (m[j]!=1)
   {
    for (k=2;k<=m[j];k++)
    if (m[j]%k==0)
    {
     w[ll]=k;
     ll++;
     m[j]=m[j]/k;
    }
   }
   m[i]=x; m[j]=y;
   for (k=0;k<=l-1;k++)
   {
    for (kk=0;kk<=ll-1;kk++)
    if (v[k]==w[kk])
    z++;
   }
   if (z==0)
   c++;
   for (k=0;k<=l-1;k++)
   v[i]=0;
   for (kk=0;kk<=ll-1;kk++)
   w[kk]=0;
   k=0;
   kk=0;
   l=0;
   ll=0;
   z=0;
   j++;
   if (j==n) {i++;j=0;} 
  }
 }
 g<<c/2;
 f.close();
 g.close();
}