import machine
import time

led_1 = machine.Pin(13, machine.Pin.OUT)
led_2 = machine.Pin(14, machine.Pin.OUT)
led_3 = machine.Pin(15, machine.Pin.OUT)
btn = machine.Pin(16, machine.Pin.IN, machine.Pin.PULL_DOWN)
buzzer = machine.Pin(12, machine.Pin.OUT)

cnt=0

while True:
    led_1.value(0)
    led_2.value(0)
    led_3.value(0)

    if btn.value()==1:
      if cnt==0:
        led_1.value(1)
        buzzer.value(1)
        time.sleep(1)
        buzzer.value(0)
      elif cnt==1:
        led_2.value(1)
      elif cnt==2:
        led_3.value(1)
      cnt+=1
      time.sleep(1)
      cnt%=3