from machine import Pin
import time

led_pins = [2, 4, 15, 5]
key_pins = [35, 32, 33, 25]

leds = [Pin(pin, Pin.OUT) for pin in led_pins]
keys = [Pin(pin, Pin.IN, Pin.PULL_UP) for pin in key_pins]

states = [0] * len(led_pins)

while True:
    for i, key in enumerate(keys):
        if not key.value():
            time.sleep_ms(9)
            if not key.value():
                states[i] = not states[i]
                leds[i].value(states[i])
                while not key.value():
                    pass