from machine import Pin
import re
from utime import sleep
Led=['a','b','c','d']
for i in range(0,4):
    Led[i]=Pin(i,Pin.OUT)
for i in range(0,16):
    N=bin(i)
    if(i<2):
        N=N.replace("0b","000")
    elif(i<4):
        N=N.replace("0b","00")
    elif(i<8):
        N=N.replace("0b","0")
    else:
        N=N.replace("0b","")
    K=0
    print(N)
    for i in N:
       print(i,K)
       Led[K].value(int(i))
       K=K+1
    sleep(2)
    for i in range(0,4):
        Led[i].value(0)
    sleep(2)