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: ['2385', 'O', 'C', '9351', '3149', '5803', 'c', 'Q', 'v', 'u', 'r', '8943', '7147']

2385, 15, 3, 9351, 3149, 5803, 3, 17, 22, 21, 18, 8943, 7147