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: ['a', '8765', 'T', '815', '2407', 'j', 'C', 'g', 'M', '1377', 'L', 'm', 'L', '5553', 'Z', 'g', '7403', 'W', 'H', '7521', 'R', '3921', 'I']

1, 8765, 20, 815, 2407, 10, 3, 7, 13, 1377, 12, 13, 12, 5553, 26, 7, 7403, 23, 8, 7521, 18, 3921, 9