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: ['139', '1481', '9661', '2197', 'N', '4459', 'D', '6127', '4981', '4065', '7839', 'h', '6169', '1757', 'X']

139, 1481, 9661, 2197, 14, 4459, 4, 6127, 4981, 4065, 7839, 8, 6169, 1757, 24