var n:longint;
    a:array[1..1000000] of boolean;
    s,i,j:longint;
    f,g:text;
function cmmdc(x,y:longint):longint;
 begin
  while x<>y do
   if y>x then
    y:=y-x
   else
    x:=x-y;
  cmmdc:=x;
 end;
begin
 assign(f,'fractii.in'); reset(f);
 assign(g,'fractii.out'); rewrite(g);
 readln(f,n);
 s:=1;
 for i:=2 to n do
  for j:=1 to i do
   if cmmdc(i,j)=1 then
    inc(s,2);
 writeln(g,s);
 close(g); close(f);
end.