var i,j,nr,n,r,a,b:longint;
    f,g:text;
begin
assign(f,'fractii.in'); reset(f);
assign(g,'fractii.out'); rewrite(g);
read(f,n);
for i:=1 to n-1 do
  for j:=i+1 to n do begin
    a:=i;
    b:=j;
    r:=a mod b;
    while r<>0 do begin
      a:=b;
      b:=r;
      r:=a mod b;
    end;
    if b=1 then nr:=nr+1;
  end;
nr:=nr*2+1;
write(g,nr);
close(g);
end.