from utime import sleep
from machine import Pin
GreenLed =  Pin(28, Pin.OUT)
BlueRed =  Pin(20, Pin.OUT)
YellowLed =  Pin(9, Pin.OUT)
RedLed =  Pin(2, Pin.OUT)
Leds = [GreenLed, BlueRed, YellowLed, RedLed]

print("Hello, Pi Pico!")
try:
    while True:
        for led in Leds:
            led.toggle()
            sleep(0.5) # Wait for USB to become ready
            led.off()
            sleep(0.5)
except KeyboardInterrupt:
    print("You're Good ...!")