var f,g:text;
    u,v,j,i,r,nr,n: longint;
    a:array[1..100]of integer;
begin
assign(f,'pairs.in');reset(f);
assign(g,'pairs.out');rewrite(g);
readln(f,n);
for i:=1 to n do
    readln(f,a[i]);
    for i:=1 to n do
    for j:=1 to n do
        begin
        if a[i]<>a[j] then begin
             u:=a[i];
             v:=a[j];
             repeat
             r:=u mod v;
             u:=v;
             v:=r;
             until r=0;
             if u=1 then nr:=nr+1;
        end;
        end;
    writeln(g,nr div 2);
    close(g);
    end.