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: ['2803', '8285', 'U', 'O', '9329', '695', '3877', '1873', '2365', 'P', '153', 'D', '8495', '7593', '4067', 'Y', 'u', '4885', 'f', 'B', 'o', '8499']

2803, 8285, 21, 15, 9329, 695, 3877, 1873, 2365, 16, 153, 4, 8495, 7593, 4067, 25, 21, 4885, 6, 2, 15, 8499