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: ['2513', '999', 'd', '9299', 'J', 'u', '611', 'u', 'o', 'R', 'y', '3097', '9621', 'Y', 'X', 'v', '7027', 'a', 'N', 't', 'u', '5637', '3077', 'K', '1637', 'q', 'z', 'E', 'Q', 'K', '4999', 'n', '1091', '1337', 't', 'e', 'R', 'O', 'Q']

2513, 999, 4, 9299, 10, 21, 611, 21, 15, 18, 25, 3097, 9621, 25, 24, 22, 7027, 1, 14, 20, 21, 5637, 3077, 11, 1637, 17, 26, 5, 17, 11, 4999, 14, 1091, 1337, 20, 5, 18, 15, 17