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: ['2521', 'u', 'm', '4081', 'F', 'b', '1579', '3385', 'z', 'E', 't', 'U', 'n', '8633', 'C', 'Q', 'K', 'O', '885', 'Q', '1997', '8521', 'J', '3873', '5397', '4235', 'S', 'W', '9173', 'u', 'e', '2637', '9951']

2521, 21, 13, 4081, 6, 2, 1579, 3385, 26, 5, 20, 21, 14, 8633, 3, 17, 11, 15, 885, 17, 1997, 8521, 10, 3873, 5397, 4235, 19, 23, 9173, 21, 5, 2637, 9951