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: ['T', '3475', 's', 'P', '1647', 'J', 't', '8983', '2505', '3655', 'r']

20, 3475, 19, 16, 1647, 10, 20, 8983, 2505, 3655, 18