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: ['8181', 'l', '8201', '2841', 'e', '4903', 'U', 'y', 'J', 'i', 'I', 'A', 'Y', '1059', 'r', '2815', 'K', 'p', '7521', '509']

8181, 12, 8201, 2841, 5, 4903, 21, 25, 10, 9, 9, 1, 25, 1059, 18, 2815, 11, 16, 7521, 509