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', 'L', 'H', '2497', '5141', 'i', '7417', 'J', '6309', 'e', 'l', 'O', 'l', 'm', '7569', 's', '9901', '4691', 'V', 'W', '8751', '5615', 'H', 'f', '1071', 'J', '1361', '6059', '3471', 'E', '9297']

16, 12, 8, 2497, 5141, 9, 7417, 10, 6309, 5, 12, 15, 12, 13, 7569, 19, 9901, 4691, 22, 23, 8751, 5615, 8, 6, 1071, 10, 1361, 6059, 3471, 5, 9297