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: ['E', 'a', 'D', '5727', '1', 'p', '9519', '8689', 'b', '2105', '9997', '8015']

5, 1, 4, 5727, 1, 16, 9519, 8689, 2, 2105, 9997, 8015