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: ['M', '2047', '1087', '4057', '2841', '4907', '251']

13, 2047, 1087, 4057, 2841, 4907, 251