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: ['f', 'a', 'v', '4929', 'a', 'Q', 'G', 'o', '281', '401', '4089', '6131', 's', 'W', 'N', '9093', '6781', '7527', '3315', 'a']

6, 1, 22, 4929, 1, 17, 7, 15, 281, 401, 4089, 6131, 19, 23, 14, 9093, 6781, 7527, 3315, 1