"""Caesar cipher solver"""

# variables go here
alphabet = "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyz"
letter_list = []

# functions here

def decode(increment_repeat=0):
    """Decodes strings."""
    for x in range(0, letter_amount):
        if (input_string[0 + increment_repeat]) == " ":
            increment_repeat += 1
            letter_list.append(" ")
        elif (input_string[0 + increment_repeat]).isnumeric():
            increment_repeat += 1
            letter_list.append(input_string[-1 + increment_repeat])
        else:
            letter = ord(input_string[0 + increment_repeat])
            increment_repeat += 1
            letter_list.append(alphabet[(letter - 97) - key])

input_string = input("string? ")
letter_amount = len(input_string)

while True:
    key = int(input("key? "))

    if 27 > key > -27:
        break

    else:
        print("key must be below 27 and above -27")

decode()

printable_string = ''.join(letter_list)
print(printable_string)