program preONI2008;
type divi=array[1..1000] of integer;
var f,g:text;
		n,i,j,nr:longint;
		v:array[1..100000] of longint;
		div1,div2:divi;


function prime(x,y:longint):boolean;
var p:boolean;
		 d:longint;
begin
d:=2;
p:=true;
if x<y then
						while (d<=x) do begin
														if (x mod d=0) and (y mod d=0) then p:=false;
														d:=d+1;
														end
			else
				 while (d<=y) do begin
														if (x mod d=0) and (y mod d=0) then p:=false;
														d:=d+1;
														end;
prime:=p;
end;


begin
assign (f,'pairs.in'); reset(f);
assign (g,'pairs.out'); rewrite(g);
read(f,n);
for i:=1 to n do readln(f,v[i]);
for i:=1 to n-1 do
	for j:=i+1 to n do
		if (v[i]<>v[j]) and prime(v[i],v[j]) then nr:=nr+1;

write(g,nr);

close(f);
close(g);
end.