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: ['2971', '2209', '6553', '1685', '5281', '7235', '7427', '4337', '3023', 'o', '3207', '2041', '4331', 'H', 'D', '8789', 'e', '9467', '9349', '1789', 'l', 'q', 'j', 'R', '7311']

2971, 2209, 6553, 1685, 5281, 7235, 7427, 4337, 3023, 15, 3207, 2041, 4331, 8, 4, 8789, 5, 9467, 9349, 1789, 12, 17, 10, 18, 7311