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', 'f', 'u', '5771', 'M', 'm', 'B', 'C', 'w', 'J', '8553', 'N', 'N', '9059', 'r', 'N', '9457']

10, 6, 21, 5771, 13, 13, 2, 3, 23, 10, 8553, 14, 14, 9059, 18, 14, 9457