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: ['u', 'T', 'S', 'L', 'w', 'W', 'y', 'L', 'H', 'Z', 'B', '4959', 'q', '8289', '2157', 'Z']

21, 20, 19, 12, 23, 23, 25, 12, 8, 26, 2, 4959, 17, 8289, 2157, 26