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: ['J', 'u', 'X', 'd', '2615', '5055', 'd', '141', 'R', '1695']

10, 21, 24, 4, 2615, 5055, 4, 141, 18, 1695