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: ['9643', 'x', 'G', '8465', '8789', '4773', 'r', 'S', '3625', '1237', '6125', '7339', 'p', 'd', '2845', '4239', 'T', 'k', '5805', '7289', 'n', 'c']

9643, 24, 7, 8465, 8789, 4773, 18, 19, 3625, 1237, 6125, 7339, 16, 4, 2845, 4239, 20, 11, 5805, 7289, 14, 3