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: ['9543', '4747', 'n', 'H', 'E', 'p', 's', 'H', '2759', 'X', 'F', '9599', '4573', 'i', '7999', '5083', 'Y', '3207', 'U', 'l', 'K', '8949', 'u']

9543, 4747, 14, 8, 5, 16, 19, 8, 2759, 24, 6, 9599, 4573, 9, 7999, 5083, 25, 3207, 21, 12, 11, 8949, 21