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: ['6307', 'A', '7033', '9519', 'n', '9453', 'n', 'K', '9915', '1193', 'v', '1669', '537', '3477', '423']

6307, 1, 7033, 9519, 14, 9453, 14, 11, 9915, 1193, 22, 1669, 537, 3477, 423