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: ['1939', '7465', 't', '8401', '161', '7451', 'd', 'H', '4957', '5765', '19', '8981', 'n', 'i', 'B', 'r', 'o', '6653', '3671', 'r', 'e', '2403', 'X', 'y', '4993', '6411', 'D', '4645', '5033', '7297']

1939, 7465, 20, 8401, 161, 7451, 4, 8, 4957, 5765, 19, 8981, 14, 9, 2, 18, 15, 6653, 3671, 18, 5, 2403, 24, 25, 4993, 6411, 4, 4645, 5033, 7297