B k q

B k qB k qB k qB k qB k qB k q
B k qB k qB k qB k qB k qB k q
B k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k qB k q