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: ['6015', 'a', '9263', 'x', 'l', 'u', 'k', 'A', '7879', 'W', 'a', '2791', '4999', 'd', 'T', '8847', '3791', '9167', '3137', '7699', 'b', 'l', '2269', 'h']

6015, 1, 9263, 24, 12, 21, 11, 1, 7879, 23, 1, 2791, 4999, 4, 20, 8847, 3791, 9167, 3137, 7699, 2, 12, 2269, 8