# to follow the fashion of 1,2...1,2,3...repeat

from machine import Pin
import time

led1 = Pin(15, Pin.OUT)
led2 = Pin(13, Pin.OUT)
led3 = Pin(10, Pin.OUT)

while True:
    led1.on()
    time.sleep(1)
    led1.off()
    
    led2.on()
    time.sleep(1)
    led2.off()

    led1.on()
    time.sleep(1)
    led1.off()

    led2.on()
    time.sleep(1)
    led2.off()

    led3.on()
    time.sleep(1)
    led3.off()