program fractii;
var f,g:text;
    m,n,i,j:longint;
function cmmdc(i,j:longint):longint;
   var r,a,b:longint;
   begin
     a:=i; b:=j;
     repeat
        r:=a mod b;
       a:=b;
       b:=r;
     until r=0;
     cmmdc:=a;
   end;
begin
assign(f,'fractii.in');
reset(f);
read(f,n);
close(f);
m:=n+n-1;
for i:=2 to n do
  for j:=i+1 to n do
    if cmmdc(i,j)=1 then m:=m+2;
assign(g,'fractii.out');
rewrite(g);
writeln(g,m);
close(g);
end.