sample_start = random.randint(0, corpus_length - message_length)
sample = corpus[sample_start:(sample_start + message_length)]
key = random.randint(1, 25)
sample_ciphertext = caesar_encipher(sample, key)
sample_start = random.randint(0, corpus_length - message_length)
sample = corpus[sample_start:(sample_start + message_length)]
key = random.randint(1, 25)
sample_ciphertext = caesar_encipher(sample, key)