program Untitled;
 var i,j,s,n:longint;

function cmmdc(a,b:integer):longint;
 var c:integer;
begin
 while (b>0) do
 begin
 c:= a mod b;
 a:=b;
 b:=c;
 end;
 cmmdc:=a;
end;

begin
 assign(input,'fractii.in');
 reset(input);
 assign(output,'fractii.out');
 rewrite(output);
 read(n);
 s:=2*n-1;
  for i:=2 to n do
   for j:=i+1 to n do
    if cmmdc(i,j) = 1 then inc(s,2);
 write(s);
end.