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', 'E', 'b', '9917', '1775', '459', 't', '3395', 'j', 'L', 'e', '503', 'p', 's', 'v', 'Y', 'F', '8675', 'I', 'b', 'u', '7621', 'y', '7251', '6317', 'l', 'P', '23', '1787', 'K', 'r', '7671']

16, 5, 2, 9917, 1775, 459, 20, 3395, 10, 12, 5, 503, 16, 19, 22, 25, 6, 8675, 9, 2, 21, 7621, 25, 7251, 6317, 12, 16, 23, 1787, 11, 18, 7671