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', 'g', '9351', 'v', 'X', 'C', 'x', '1573', 'z', 'a', '2543', 'w', '5921']

15, 7, 9351, 22, 24, 3, 24, 1573, 26, 1, 2543, 23, 5921