import machine
from machine import Pin
import time
led1=Pin(2,Pin.OUT)
led2=Pin(4,Pin.OUT)
while True:
    led1.on()
    time.sleep(0.5)
    led1.off()
    time.sleep(0.5)
    led2.on()
    time.sleep(0.5)
    led2.off()
    time.sleep(0.5)