code 1

message = 'hello'
mode = 'encrypt'

key = 1

SYMBOLS = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890 !?.'



translated = ''

for symbol in message:
    if symbol in SYMBOLS:
        symbolIndex = SYMBOLS.find(symbol)

        if mode == 'encrypt':
            tranlatedIndex = symbolIndex + key
        elif mode == 'decrypt':
            tranlatedIndex = symbolIndex - key
        if tranlatedIndex >= len(SYMBOLS):
            tranlatedIndex = tranlatedIndex - len(SYMBOLS)
        elif tranlatedIndex < 0:
            tranlatedIndex = tranlatedIndex + len(SYMBOLS)
        translated = translated + SYMBOLS[tranlatedIndex]
    else:
        translated = translated + symbol
print(translated)