# a = 10
# b = 20

# c = b / a
# print("c", c)
# print("mod", b % a)
# print("**", 2**2)
# print("//", 4//3)

# print("a==b", a == b)
# print("a!=b", a != b)

# print('2^1', 2^1)

# arr = [1,0,2,1]
# arr2 = []
# for index in range(len(arr)-1):
#   tmp = arr[index] ^ arr[index+1]
#   arr2.append(tmp)

encoded = [6,2,7,3]
first = 4
arr = []
arr.append(first)
for index in range(len(encoded)):
  i = encoded[index]
  s = i ^ first
  arr.append(s)
  first = s

print(arr)