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: ['3315', 'i', '551', '3875', 'O', '6651', '371', 'T', 'b', '2263', 'I', 'V', 'y', 'Q', 'p', '7971', 'y', '639', 'U', '1387', '6137', 'l', 'O', '5273', '7573', 'K', 'A', 'P', 'C']

3315, 9, 551, 3875, 15, 6651, 371, 20, 2, 2263, 9, 22, 25, 17, 16, 7971, 25, 639, 21, 1387, 6137, 12, 15, 5273, 7573, 11, 1, 16, 3