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: ['399', '4883', '7819', 's', 'k', 'C', '8499', '2787', '6309', '3959', 'S', 'M', '7329', '3117', 'N', '5665', 'U', '3465', '6609', '3093', 'l', '1187', '1035', 'j', 'S', '5999', '5071']

399, 4883, 7819, 19, 11, 3, 8499, 2787, 6309, 3959, 19, 13, 7329, 3117, 14, 5665, 21, 3465, 6609, 3093, 12, 1187, 1035, 10, 19, 5999, 5071