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: ['t', '9021', 'G', 'h', '8751', '5801', '8727', 'b', 'F', 'J', 'j', 'G', '5421', 'S', '3339']

20, 9021, 7, 8, 8751, 5801, 8727, 2, 6, 10, 10, 7, 5421, 19, 3339