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: ['I', 'W', '5203', '1981', 'e', 'o', 'D', '6287', '1415', '5175', 'H', 'N', '4299', '3391', 'H', 'I', 'e', 'u', 'Y', '7025', 'd', 'X', '1127', '5165', '4349', 'w', '9421', 't', 'E', 'a', '7135', '3691', 'A', 'S', '2559', 'P', 'E']

9, 23, 5203, 1981, 5, 15, 4, 6287, 1415, 5175, 8, 14, 4299, 3391, 8, 9, 5, 21, 25, 7025, 4, 24, 1127, 5165, 4349, 23, 9421, 20, 5, 1, 7135, 3691, 1, 19, 2559, 16, 5