def main():
    shift = (ord('C') - ord('y')) % 26

    ctext = "XVIEWYWI"
    plaintext = []

    for ch in ctext:
        if ch.isalpha():
            base = ord('a')
            shifted = (ord(ch.lower()) - base - shift) % 26 + base
            plaintext.append(chr(shifted))
        else:
            plaintext.append(ch)

    print(f"Attack type: Known plaintext attack")
    print(f"Ciphertext: {ctext}")
    print(f"Decrypted: {''.join(plaintext)}")

if __name__ == '__main__':
    main()