import string
russian = 'абвгдеёжзийклмнопрстуфхцчшщъыьэюяАБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ'
again = True

class LengthError(Exception):
    def __init__(self):
        print('At least 2 characters are required')

class NumError(Exception):
    def __init__(Self):
        print('Numbers are not allowed')

while again == True:
    try:
        text = input('Your text goes here: ')
        text = text.replace(" ","")
        if len(text)<2:
            raise LengthError
        else:
            for item in text:
                if item not in string.ascii_lowercase and item not in russian:
                    raise NumError
    except:
        print('Try again')
        pass
    else:
        if text == text[::-1]:
            print('This is a palindrome')
        else:
            print("This isn't a palindrome")

        while True:
            ask = input("Do you want to try again? y/n: ")
            if ask == 'y':
                break
            elif ask == 'n':
                again = False
                break
            else:
                print('Invalid response')