Problem with $2-$letter units in an affine encryption system. All these problems can be solved by hand.

All arithmetic is performed in

$.$ X below is a

matrix, as is

$,$ while

is a

matrix.

Encryption function:

In this problem, neither

nor

are known to us but we made an attack on this cryptosystem and discovered that the plaintext 'NENAGH' is encrypted as 'VFHHWI'. That is$,$ NENAGH

VFHHWI.

Decrypt 'LAUHGI' in this affine system. LAUHGI

$($input a $6-$letter string as your answer: $2+2+2)$