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: ['8591', 'L', '2513', 'U', '8165', 'N', '7247', '6357', 'y', '4259', '789', 'H', '4345', 'z', 'G']

8591, 12, 2513, 21, 8165, 14, 7247, 6357, 25, 4259, 789, 8, 4345, 26, 7