function prim(a,b:longint):boolean;
var r:longint;
begin
 r:=a mod b;
 while r<>0 do begin
  a:=b; b:=r; r:=a mod b;
 end;
 prim:=b=1;
end;

var n,i,j,k:longint;
    v:array [1..100000] of longint;
begin
 assign(input,'pairs.in'); reset(input);
 assign(output,'pairs.out'); rewrite(output);
  readln(n);
   for i:=1 to n do readln(v[i]);
  for i:=1 to n do
   for j:=i+1 to n do
    if prim(v[i],v[j]) then inc(k);
  writeln(k);
 close(input); close(output);
end.