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: ['R', 'D', 'I', '2531', '7409', 'd', 'a', 'Z', '2501', 'h', 't', 'u', '3141', 'w']

18, 4, 9, 2531, 7409, 4, 1, 26, 2501, 8, 20, 21, 3141, 23