from microbit import *

display.off()

pin16.write_digital(0)
pin15.write_digital(0)
    
while True:

    if button_b.was_pressed():
        pin16.write_digital(1) 
        pin15.write_digital(0)   
        sleep(500)
        pin16.write_digital(0)

    if button_a.was_pressed():
        pin16.write_digital(0)
        pin15.write_digital(1)    
        sleep(500)
        pin15.write_digital(0)