For example, Caesar's cipher can have a code book below $($the key value is $3).$

Plain: ABCDEFGHIJKLMNOPQRSTUVWXYZ

Cipher: DEFGHIJKLMNOPQRSTUVWXYZABC

If the key value $4$ is selected in the substitution cipher, the string "APPLE" can be

encrypted into "ETTPI" as shown below.

Your task is to write an MIPS assembly language program to encrypt a plaintext string,

assuming that the key is $3.$

Your program should meet the following requirements:

Prompt for and read an input string. Initially, the input string can be stored in a

static space allocated in the main memory.

Prompt to read the cipher key $($integer$)$ and store it in a register.

The input consists of a string that contains only uppercase letters without other

characters or special characters such as lowercase, spaces, periods, etc.

Write a function to dynamically allocate memory to hold and encrypt the output

string, which is the same length as the input string. Note: use stack to store the

parameters in the function $($ $$a0$ for the address for the input string, $$a1$ for the

cipher key, and $ra for the value of $ra register, refer to the previous lab.$)$

Write a function to display$/$print the content in the dynamically allocated memory.

Write a function to calculate the length of the input string and show the length of

the dynamically allocated string.