B p q

B p qB p qB p qB p qB p qB p q
B p qB p qB p qB p qB p qB p q
B p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p qB p q