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alphabet = 'abcdefghijklmnopqrstuvwxyz'


def encrypt(cleartext):
    cyphertext = ''
    for char in cleartext:
        if char in alphabet:
            newpos = (alphabet.find(char) + 13) % 26
            cyphertext += alphabet[newpos]
        else:
            cyphertext += char
    return cyphertext


cleartext = input('Cleartext: ')
cleartext = cleartext.lower()
print(encrypt(cleartext))