P s

P sP sP sP sP sP s
P sP sP sP sP sP s
P sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP sP s