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: ['7303', 'W', '4229', '993', 'u', '8487', 'y', '2005', '1999', '3907', '6903', '4961', 'y', 'q', 'j', '8111', 'P', 'l', 'a']

7303, 23, 4229, 993, 21, 8487, 25, 2005, 1999, 3907, 6903, 4961, 25, 17, 10, 8111, 16, 12, 1