Cоnsider the оffline cаching prоblem. Suppose we hаve а cache of size 4 (i.e., can hold four items at a time) and is initially empty. Let be the sequence of item requests. Use the Farthest-in-Future algorithm assuming that you start from an empty cache. Show the configuration of the cache after the first request for item (in the eighth position of the sequence) is satisfied. Enter your response in the format of four comma-separated letters in alphabetical order. Example response: w,x,y,z