You will implement the following encryption scheme we discussed in class:

E$\_$k$($x$)=$ ax $+$ b mod $26,$ where key k $=($a$,$ b$)$

Implement a cipher to operate on numbers in Z$26=\{0,1,...,25\}.$ Encryption is provided:

def encrypt$($x$,$ a$,$ b$)$:

return $($a $*$ x $+$ b$)\%26$

Write a function named "decrypt" that completes the encrypt function. You will need a helper function or data structure for decryption; name it "INVERSE".