from machine import Pin
from time import sleep

led1 = Pin(2, Pin.OUT)
led2 = Pin(42, Pin.OUT)
led3 = Pin(41, Pin.OUT)
led4 = Pin(40, Pin.OUT)
while True:
    led1.on()
    sleep(1)
    led1.off()
    sleep(1)
    
    led2.on()
    sleep(1)
    led2.off()
    
    sleep(1)
    led3.on()
    sleep(1)
    led3.off()
    
    sleep(1)
    led4.on()
    sleep(1)
    led4.off()
    sleep(1)