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: ['5711', '51', 'g', '7421', 'q', '7429', 'j', 'B']

5711, 51, 7, 7421, 17, 7429, 10, 2