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: ['5405', '4255', '2739', '2127', '8945', 'Q', 'U', 'B', '1743', '1877', 'Q', '6715', 'f', 'J']

5405, 4255, 2739, 2127, 8945, 17, 21, 2, 1743, 1877, 17, 6715, 6, 10