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: ['5465', '7321', '8753', 'g', 'v', '5987', 'S', '1273', 'w', 'h', 'j', 't', 'R', '891', '5665', '5873', 'F', '3673', '8755', 'o', 'u', 'U', 'K', 'n', '3687', '5857', '9713', 'S', '497', '3969']

5465, 7321, 8753, 7, 22, 5987, 19, 1273, 23, 8, 10, 20, 18, 891, 5665, 5873, 6, 3673, 8755, 15, 21, 21, 11, 14, 3687, 5857, 9713, 19, 497, 3969