#include <iostream>
#include <fstream>
using namespace std;

int cmmdc(int a, int b)
{
	while (a!=b)
	{
		if (a>b)
			a=a-b;
		else 
			b=b-a;
	}	
	
return a;	
}	

int main()
{ ofstream out("pairs.out"); ifstream in("pairs.in");
  int n, v[20], nr=0;;
  
  
 in>>n;
  for (int i=1; i<=n; i++)
	in>>v[i]; 
  
  for (int i=1; i<=n; i++)
	  for (int j=i; j<=n; j++)
		  if (cmmdc(v[i],v[j]) == 1) nr++;

	  out<<nr;
 

 in.close();
 out.close();
return 0;
}