write an assembly code 8086 (16 bit ) that do the following

1- ask the user to enter text that is more than 0 and less than or equal 20 letters

2- and ask the user to enter a key

between 0 and 9

3- the cipher should convert the last bit of each letter ( from 0 to 1 or from 1 to 0) and then add it to the key that the user enter .

4- do the decrypt ( the program should encrypt and decrypt )

5- please make sure to ask the user if he want to decrypt enter D if he want Encrypt enter E.

6- please i need an assembly code

do not explain how to write the code.

Only i need you to write the code

7- thank you