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: ['2779', 'u', '8543', '1605', '987', '9935', 'a', 'f', 'd', 'u']

2779, 21, 8543, 1605, 987, 9935, 1, 6, 4, 21