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: ['O', 'l', '901', 'b', '4355', 'Q', '6953', '9375', 'Q', '5107']

15, 12, 901, 2, 4355, 17, 6953, 9375, 17, 5107