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: ['4513', '2709', 't', 'J', '9747', 'A', 'k', '5007', '5271', 'm', '6117', 'N', '4069', 't', 'i', 'F', 'U', 'G', 'd']

4513, 2709, 20, 10, 9747, 1, 11, 5007, 5271, 13, 6117, 14, 4069, 20, 9, 6, 21, 7, 4