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: ['J', '1987', 'H', 'M', 'q', 'Y', '4491', '9765', 'H', 'I', 'X', 'd', 'w', 'T', 'z']

10, 1987, 8, 13, 17, 25, 4491, 9765, 8, 9, 24, 4, 23, 20, 26