#include<fstream.h>

int v[100000],n,p=0;

ifstream citeste ("pairs.in");
ofstream scrie ("pairs.out");

int prime (int a,int b)
{
while (a!=b) 
	if (a>b) a-=b;
		else b-=a;
if (a>1) return 0;
	else return 1;
}

int pairs (int a,int b)
{
int x;
if (a==b) return 0;
x=prime (a,b);
return x;
}

int main ()
{
citeste>>n;
int i,j;
for (i=1;i<=n;i++) citeste>>v[i];
for (i=1;i<n;i++)
	for (j=i;j<=n;j++) 
		if (pairs (v[i],v[j])) p++;
scrie<<p;
return 0;
}