import machine
import utime

led_red=machine.Pin(15,machine.Pin.OUT)
led_yellow=machine.Pin(14,machine.Pin.OUT)
led_green=machine.Pin(13,machine.Pin.OUT)

while True:
    led_red.value(1)
    utime.sleep(5)
    led_yellow.value(1)
    utime.sleep(2)
    led_red.value(0)
    led_yellow.value(0)
    led_green.value(1)
    utime.sleep(5)
    led_green.value(0)
    led_yellow.value(1)
    utime.sleep(5)
    led_yellow.value(0)