from machine import Pin
from utime import sleep

led_rojo = Pin(3, Pin.OUT)
led_amarillo = Pin(4, Pin.OUT)
led_verde = Pin(5, Pin.OUT)

while True:
    led_rojo.on()
    sleep(10)
    led_rojo.off()
    led_amarillo.on()
    sleep(1)
    led_amarillo.off()
    led_verde.on()
    sleep(10)
    led_verde.off()
    led_amarillo.on()
    sleep(1)
    led_amarillo.off()