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: ['d', '903', 'N', 'n', '1959', 'U', 'Z', 'v', 'f', '6207', '4947', '9471', 'v', '481', 'Z', '163']

4, 903, 14, 14, 1959, 21, 26, 22, 6, 6207, 4947, 9471, 22, 481, 26, 163