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: ['P', 'U', 'f', 'D', '207', 'P', '7129', 'W', 'G', '4589', 'k', 'r', '9745', 'i', 's', '4711', 'I', '2803', '8947', 't', 'p', 'q', '6047', 'e', '4239', 'f', '9103']

16, 21, 6, 4, 207, 16, 7129, 23, 7, 4589, 11, 18, 9745, 9, 19, 4711, 9, 2803, 8947, 20, 16, 17, 6047, 5, 4239, 6, 9103