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: ['519', '6529', '9775', '4469', 'Y', '1659', '6733', '4865', 'V', '3563', 'T', 'J', '5537', '8023', 'C', 'z', 'E', 'e', 'O']

519, 6529, 9775, 4469, 25, 1659, 6733, 4865, 22, 3563, 20, 10, 5537, 8023, 3, 26, 5, 5, 15