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: ['4619', 'C', 'A', 'x', 'B', 'Y', '8045', '9903', '1887']

4619, 3, 1, 24, 2, 25, 8045, 9903, 1887