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: ['8509', '4369', '63', 'Z', '2837', '1783', 'k', '8081', '9369', 'k', 'T', 'a', '4797', 'k', '7303', '1723', '4969', '3305', 'l', '495', '1261', 'f', '6265', 'i', '9231', 'y', 'W', 'g', '1709', 'D']

8509, 4369, 63, 26, 2837, 1783, 11, 8081, 9369, 11, 20, 1, 4797, 11, 7303, 1723, 4969, 3305, 12, 495, 1261, 6, 6265, 9, 9231, 25, 23, 7, 1709, 4