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: ['2123', '4459', '489', '5889', '4283', 'Y', '4781', 'P', 'u', 'd', '8249']

2123, 4459, 489, 5889, 4283, 25, 4781, 16, 21, 4, 8249