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: ['O', 'X', 'j', '6499', 'I', '359', '1913', 'M', '6771', 's', '1621', '8259', 'E', 'H', 'E', '3699', '3473', 'Q', 'c', 'A', '6265', 'n', 'L', '7003', 'H', '4743', '8579']

15, 24, 10, 6499, 9, 359, 1913, 13, 6771, 19, 1621, 8259, 5, 8, 5, 3699, 3473, 17, 3, 1, 6265, 14, 12, 7003, 8, 4743, 8579