type interv=1..1000000;
var n:1..100000;
  m:array [1..100000] of interv;
  fin,fout:text;

 procedure citire;
  var i:1..100000;
  begin
   readln(fin,n);
   for i:=1 to n do readln(fin,m[i]);
  end;

 function prime(a,b:interv):boolean;
  var r:interv;
  begin
   repeat

     r:=a mod b;
     a:=b;
     b:=r;
   until r=0;
   if a=1 then prime:=true
   else prime:=false;
  end;

 procedure perechi;
  var i,j,p:0..100000;
  begin
   p:=0;
   for i:=1 to n do
     for j:=i+1 to n do
       if prime(m[i],m[j]) then p:=p+1;
   write(fout,p);
  end;

begin
  assign(fin,'pairs.in');
  assign(fout,'pairs.out');
  reset(fin);
  rewrite(fout);
  citire;
  perechi;
  close(fin);
  close(fout);
end.