program fractii;
var f1,f2:text;
    i,j,nr,r,n,d,a0,b0:longint;
begin
assign(f1,'fractii.in');
reset(f1);
read(f1,n);
close(f1);
assign(f2,'fractii.out');
rewrite(f2);
  nr:=0;
for i:=1 to n-1 do
  for j:=i+1 to n do
    begin
    a0:=i;
    b0:=j;
    repeat
      r:=a0 mod b0;
      a0:=b0;
      b0:=r;
    until r=0;
    d:=a0;
    if d=1 then
      nr:=nr+1;
    end;
nr:=2*nr+1;
writeln(f2,nr);
close(f2);

end.