406680: GYM102483 K Kleptography

John likes simple ciphers. He had been using the "Caesar" cipher to encrypt his diary until recently, when he learned a hard lesson about its strength by catching his sister Mary browsing through the diary without any problems.

Rapidly searching for an alternative, John found a solution: the famous "Autokey" cipher. He uses a version that takes the $$$26$$$ lower-case letters 'a'–'z' and internally translates them in alphabetical order to the numbers $$$0$$$ to $$$25$$$.

The encryption key $$$k$$$ begins with a secret prefix of $$$n$$$ letters. Each of the remaining letters of the key is copied from the letters of the plaintext $$$a$$$, so that $$$k_{n+i} = a_{i}$$$ for $$$i \geq 1$$$. Encryption of the plaintext $$$a$$$ to the ciphertext $$$b$$$ follows the formula $$$b_i = a_i + k_i \bmod 26$$$.

Mary is not easily discouraged. She was able to get a peek at the last $$$n$$$ letters John typed into his diary on the family computer before he noticed her, quickly encrypted the text document with a click, and left. This could be her chance.

The input consists of:

• One line with two integers $$$n$$$ and $$$m$$$ ($$$1 \le n \le 30$$$, $$$n + 1 \le m \le 100$$$), where $$$n$$$ is the length of the keyword as well as the number of letters Mary saw, and $$$m$$$ is the length of the text.
• One line with $$$n$$$ lower-case letters, the last $$$n$$$ letters of the plaintext.
• One line with $$$m$$$ lower-case letters, the whole ciphertext.

Output the plaintext of John's diary.

5 16
again
pirpumsemoystoal

marywasnosyagain

1 12
d
fzvfkdocukfu

shortkeyword