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: ['2987', 'k', 'Z', 'Z', '2231', '9129', 'C', 'q', '1777', 'm', 'G', '4773', 'X', '4643', 'n']

2987, 11, 26, 26, 2231, 9129, 3, 17, 1777, 13, 7, 4773, 24, 4643, 14