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: ['A', 'S', 'I', 'D', '4791', '4747', '413', 'I', 'B', '4469']

1, 19, 9, 4, 4791, 4747, 413, 9, 2, 4469