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: ['b', 'b', 'a', '3147', 'P', 'j', 'N', 'm', '1087']

2, 2, 1, 3147, 16, 10, 14, 13, 1087