def Encrypt(text, key):
    result = ""
    for i in range(len(text)):
        char = text[i]
        if(char==" "):
            result+=" "
        elif (char.isupper()):
            result += chr((ord(char) + key-65) % 26 + 65)
        else:
            result += chr((ord(char) + key - 97) % 26 + 97)
    return result



def Decrypt(text, key):
    result = ""
    for i in range(len(text)):
        char = text[i]
        if(char==" "):
            result+=" "
        elif (char.isupper()):
            result += chr((ord(char) - key-65) % 26 + 65)
        else:
            result += chr((ord(char) - key - 97) % 26 + 97)
    return result

    

print(Encrypt("Hello world", 29))
print(Decrypt("Khoor zruog", 29))