from time import sleep
from machine import Pin 

while True:
    for i in range(1,6,1):
        led=Pin(i,Pin.OUT)
        led.on()
        sleep(0.3)
        led.off()
    for i in range(4,1,-1):
        led=Pin(i,Pin.OUT)
        led.on()
        sleep(0.3)
        led.off()