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: ['7791', 'e', '6881', 'E', '4979', 'd', '8715']

7791, 5, 6881, 5, 4979, 4, 8715