#include <fstream.h>
#include <iostream.h>

#define IN "pairs.in"
#define OUT "pairs.out"
#define dim 100004

ifstream fin(IN);
ofstream fout(OUT);

long n;
long x[dim];
long cont;

void citire();
int bun(long x,long y);

int main()
{
 long i,j;

 citire();

 for(i=1;i<=n;i++)
  for(j=i+1;j<=n;j++)
   if(bun(x[i],x[j])==1)
    cont++;

 fout<<cont;
 fout.close();
 return 0;
}

void citire()
{
 long i;

 fin>>n;

 for(i=1;i<=n;i++)
  fin>>x[i];
 fin.close();
}

int bun(long x,long y)
{
 long d=3;
 long r;

 if(x<y)
  r=x;
 else
  r=y;

 if(x%2==0 && y%2==0)
  return 0;

 for(d=3;d<=r;d=d+2)
  if(x%d==0 && y%d==0)
   return 0;

 return 1;
}