from machine import Pin
from time import sleep
led=Pin(23,Pin.OUT)
ledj=Pin(21,Pin.OUT)
ledr=Pin(12,Pin.OUT)

while True :
    led.on()
    ledj.off()
    ledr.off()
    sleep(3)
    ledj.on()
    led.off()
    ledr.off()
    sleep(2)
    ledr.on()
    led.off()
    ledj.off()
    sleep(1)