please explain all steps. Thanks

Files on disks are called "sequential" if each page in a file points to its successor, which may be any page on the disk. This method can write a page and read the first page in the file in O(1), as well as read the ith page in 0(1), once you have read the ilst page. Reading the ith page from scratch take 0(i). BeeLate Disks have hired you to improve this read bound, but none of the existing speed gaurantees can get any worse without losing customers to Moogle Storage, and any solution can't be too involved because it will eat into valuable foosball time at BeeLate HQ. Show how by adding just one additional pointer per node you can keep all the other properties, but allow the ith page to be read in time O(logzi)