import machine
from machine import Pin

S2=Pin(1, Pin.OUT)
S1=Pin(2, Pin.OUT)
S0=Pin(3, Pin.OUT)
E1=Pin(4, Pin.IN, Pin.PULL_UP)
E2=Pin(5, Pin.IN, Pin.PULL_UP)
E3=Pin(6, Pin.IN, Pin.PULL_UP)
E4=Pin(7, Pin.IN, Pin.PULL_UP)

while True:
    A=E1.value()
    B=E2.value()
    C=E3.value()
    D=E4.value()

    suma2=((A and B and D) or (B and C and D) or (A and C))
    suma1=((A and not C and not D) or (A and not B and not C) or (not A and not B and C) or (not A and  C and not D) or (not A and B and not C and D) or (A and B and C and D))
    suma0=((not B and D) or (B and not D))
    S2.value(suma2)
    S1.value(suma1)
    S0.value(suma0)