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: ['B', '3045', 'M', 'I', '8007', 'f', '8751', '2911', '3367', 'B', 'U', '9311', 'I', '1531', 'O', 'f', 'x', '6261', '5611', 'N', 'y', '563', 'Q', 'r', '4279', '4619']

2, 3045, 13, 9, 8007, 6, 8751, 2911, 3367, 2, 21, 9311, 9, 1531, 15, 6, 24, 6261, 5611, 14, 25, 563, 17, 18, 4279, 4619