Having trouble writing this program! Please help!

The following two strings represent encryption keys which can be used for a simple character- substitution encryption program. Plain Key = "ABCDEFGHIJKLMNOPORS 1234567890., " EnigmaKey = "T' 60US7, ORW 89HC3YJMKEIB1QVDXFP52ZN4ALG. To encrypt a string, you would: 1. Find that character's index (position) in PlainKey. 2. Substitute the character at the same index in EnigmaKey. To decrypt a string, you would do the same thing with the opposite keys, i.e. 1. Find the encrypted characters index position) in EnigmaKey. 2. Substitute the character at the same index in PlainKey. The following string represents a message that has already been encrypted using these keys and algorithm: Cypher = "OV HEUV6TMJGV' KMVOV6T9.MVUTMVTV H UVH9UL" Write a program to decrypt and display this message