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: ['4869', 's', 'p', 'v', 'm', 'u', '3491', '5301', '3187', 'v', 'M', '4615', '6047', 'L', 'h', 'b', '2745', '7867', 'm', 'S', '9', '3677', '6851', 'N', '5991', '8841', 'V', '5997', 'Q', '5989', 'u', 'O', '5311']

4869, 19, 16, 22, 13, 21, 3491, 5301, 3187, 22, 13, 4615, 6047, 12, 8, 2, 2745, 7867, 13, 19, 9, 3677, 6851, 14, 5991, 8841, 22, 5997, 17, 5989, 21, 15, 5311