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: ['3961', 'Y', 'u', '2163', 'f', 't', '3781', '461']

3961, 25, 21, 2163, 6, 20, 3781, 461