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: ['v', 'f', '5891', '5185', 't', '6629', '5', 'f', 'c', '7413', 'b', '7645', '73', 'o', 'l', '1423']

22, 6, 5891, 5185, 20, 6629, 5, 6, 3, 7413, 2, 7645, 73, 15, 12, 1423