program pair;
type vector=array[1..10000] of integer;
var  n,i,nr,j:integer;
     a:vector;
     f:text;
 function prime(x,y:longint):boolean;
  var s:integer;
      min:longint;
 begin
  if x>y then
   min:=y
  else
   min:=x;
   min:=min div 2;
  prime:=true;
 for s:= 2 to min do
  if (x mod s =0) and (y mod s = 0 )then
   prime:=false;
  end;
begin
assign(f,'pairs.in');
reset(f);
read(f,n);
for i := 1 to n do
 read(f,a[i]);
 nr:=0;
for i := 1 to n-1 do
 for j:= i+1 to n do
 if (a[i]<>a[j]) and (prime(a[i],a[j])=true) then
      nr:=nr+1;
close(f);
assign(f,'pairs.out');
rewrite(f);
write(f,nr);
close(f);
end.