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', 'O', 'B', '5579', '2155', 'w', '3361', '963', 'Z', 'l', '8667', '8669', 'l', '4255', '3439', 'Z', '4817', '5355', '3291', '9327', 'U', 'D', 'W', '4009']

16, 15, 2, 5579, 2155, 23, 3361, 963, 26, 12, 8667, 8669, 12, 4255, 3439, 26, 4817, 5355, 3291, 9327, 21, 4, 23, 4009