from time import sleep
sleep(0.1) # Wait for USB to become ready

print("Hello, Pi Pico!")
from machine import Pin

ledPins = [16,17,18,19]
leds = []
for i in range(len(ledPins)):
  leds.append(Pin(ledPins[i], Pin.OUT))


while True:
    for led in leds:
        led.on()
        sleep(0.5)
    for led in leds:
        led.off()
    sleep(1)