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: ['W', 'A', '4455', '9201', 'B', '2315', '2057', '5139', 'f', 'M', 'l', 'h', '5639', 'd', '125', '5483', 'I', '6603', '4363', 'B', 'O', 'z', '6093', 'x', 'p', '6141', '5013', 'n', 'W', '1603']

23, 1, 4455, 9201, 2, 2315, 2057, 5139, 6, 13, 12, 8, 5639, 4, 125, 5483, 9, 6603, 4363, 2, 15, 26, 6093, 24, 16, 6141, 5013, 14, 23, 1603