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: ['U', '7017', 'w', 'Z', 'T', 'X', '8699', 'S', 'R']

21, 7017, 23, 26, 20, 24, 8699, 19, 18