Definition: In this task, you are given an input list A. You need to convert all the alphabets in the list with a number representing their position in the English alphabet. E.g., replace A by 1, B by 2, a by 1, b by 2, and so on.
Input: ['P', '6869', '4731', '9913', 'M', '2929', 'a', 'i', '5737', 'O', '3347', 'q', 't', '4809', 'P', '2601', '3841', '3901', '6075', 'h', '3731', 'r', '899', 'P', 'm', '5445', 'W', '1345', 'W', 't', '5905', '6409', 'V', '3369', 'X']

16, 6869, 4731, 9913, 13, 2929, 1, 9, 5737, 15, 3347, 17, 20, 4809, 16, 2601, 3841, 3901, 6075, 8, 3731, 18, 899, 16, 13, 5445, 23, 1345, 23, 20, 5905, 6409, 22, 3369, 24