import time
from machine import Pin

led1=Pin(21, Pin.OUT)
led2=Pin(23, Pin.OUT)
led3=Pin(22, Pin.OUT)

while True:
    led1.value(1)
    time.sleep(5)
    led1.value(0)

    led2.value(1)
    time.sleep(5)
    led2.value(0)

    for i in range(3):
        led3.value(1)
        time.sleep(0.3)
        led3.value(0)
        time.sleep(0.3)