program fractii;
var n:int64;
    nf:int64;
    a,b,i,j,r:longint;
    f,g:text;
begin
  assign(f,'fractii.in');
  assign(g,'fractii.out');
  reset(f);
  rewrite(g);
  readln(f,n);
  nf:=(n*(n-1)) div 2;
  for j:=1 to n do
    for i:=1 to j-1 do
      if (i<>1) and (j mod i = 0) then nf := nf -1
      else
      begin
        a:=j;
        b:=i;
        r:=j mod i;
        while r<>0 do
        begin
          a:=b;
          b:=r;
          r:=a mod b;
        end;
        if b<>1 then nf:=nf-1;
      end;
  writeln(g, 2*nf + 1);
  close(f);
  close(g);
end.