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: ['H', '2533', 'U', '6299', '9655', '2365', '9139', '6159', '6523', 'j', '5653', '9785', 'C']

8, 2533, 21, 6299, 9655, 2365, 9139, 6159, 6523, 10, 5653, 9785, 3