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', '2877', 'r', 'e', 'n', 'A', '4115', '6491', 'N', '5689', 'x', '87', 'A', '7575', '7175', 'D', 'e', 'L', 'p', '6671', '4921', 'A', '7255', '4653', 'u']

16, 2877, 18, 5, 14, 1, 4115, 6491, 14, 5689, 24, 87, 1, 7575, 7175, 4, 5, 12, 16, 6671, 4921, 1, 7255, 4653, 21