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: ['5497', 'u', '8739', '8487', '391', 'V', '7131', '8239', '3373']

5497, 21, 8739, 8487, 391, 22, 7131, 8239, 3373