var i,j,ant,act:longint;
n:longint;
f,g:text;
function cmmdc(a,b:longint):longint;
var r:longint;
begin
r:=a mod b;
while r<>0 do
  begin
  a:=b;
  b:=r;
  r:=a mod b;
  end;
cmmdc:=b;
end;
begin
assign(f,'fractii.in');
reset(f);
assign(g,'fractii.out');
rewrite(g);
readln(f,n);
close(f);
if n=1 then writeln(g,'1')
else if n=2 then writeln(g,'2')
  else
  begin
  act:=3;
  for i:=3 to n do
  for j:=1to i-1 do
      if cmmdc(i,j)=1 then act:=act+2;
  writeln(g,act);
  end;
close(g);
end.