The decryption algorithm for the affine cipher is defined below

D([a,b],C) = a^-1(C - b) mod 26

where a^-1 is the modular multiplicative inverse of a modulo 26. That is, it satisfies the equation aa^-1 = 1 mod 26. Now, implement the encryption function for the affine cipher. Assume that a message is encrypted using the affine cipher and the resulting ciphertext is as follows

'fmxv ceotx oc txy qkndlot!'

You can assume that the key consists of a pair of integers (a, b), both in {1,...,25} with a not divisible by 2 or 13. Also, the function should work on strings, and leave any non-alphabetic characters unchanged. What would be the values of m and key k in the above case? (Hint: you need to do an exhaustive search or brute force attack over all possible keys.)