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: ['o', 't', 'F', '9407', '4489', '9453', 'n', 'R', 'H', 'B', '4067', 'R', 'T', 'E', 's', '7641', '1861', '9925', 'A', 'V', '8765', '8987', '4239', 'o', 'U', '2847', '9007', 'U', 'E', '9719']

15, 20, 6, 9407, 4489, 9453, 14, 18, 8, 2, 4067, 18, 20, 5, 19, 7641, 1861, 9925, 1, 22, 8765, 8987, 4239, 15, 21, 2847, 9007, 21, 5, 9719