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: ['6499', 'A', '5971', '8887', '3945', '8505']

6499, 1, 5971, 8887, 3945, 8505