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: ['d', 'm', '3887', '563', 'Y', 'R', '4259', 'X', 'b', '7609', 'z', '3005', 'v', 'C', 'z']

4, 13, 3887, 563, 25, 18, 4259, 24, 2, 7609, 26, 3005, 22, 3, 26