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: ['3531', '457', '6707', 'X', 'g', 'I', '5919', 'y', 'D', '651', 'q', '5475', '5389', 'y', 'u', 'J', 'o', '3989', '3113', '2185', '7423', 'a', '3969', '1069', '1899', 'i', '599', 'X', '2945', 'u', 'R']

3531, 457, 6707, 24, 7, 9, 5919, 25, 4, 651, 17, 5475, 5389, 25, 21, 10, 15, 3989, 3113, 2185, 7423, 1, 3969, 1069, 1899, 9, 599, 24, 2945, 21, 18