var p,q,n,nr:longint;
f,g:text;
function cmmdc(a,b:longint):longint;
var r:longint;
begin
while r<>0 do
 begin
  r:=a MOD b;
  a:=b;
  b:=r;
 end;
cmmdc:=a;
end;
begin
nr:=n;
assign(f,'fractii.in');reset(f);
read(f,n);close(f);
for p:=1 to n-1 do
	for q:=p+1 to n do
	if cmmdc(p,q)=1 then
		nr:=nr+2;
assign(g,'fractii.out');rewrite(g);
write(g,nr);
close(g);
end.