#include <fstream.h>

int prime(unsigned int n, unsigned int p)
{
	while(n!=0&&p!=0)
   {
      if(n>=p)
         n-=p;
      else
      	p-=n;
   }
   if(n==0&&p==1)
   	return 1;
   return 0;
}

void main()
{
	unsigned int n, A[100000], i, j, c=0;
   ifstream in("pairs.in");
   in>>n;
   for(i=1; i<=n; i++)
   	in>>A[i];
   in.close();
   for(i=1; i<n; i++)
      for(j=i+1; j<=n; j++)
         if(prime(A[i],A[j]))
            c++;
   ofstream out("pairs.out");
   out<<c<<endl;
   out.close();
}