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: ['t', 'J', 'r', '9973', 'U', 'W', '4015', '7875', '7151', '6997', '2317', 'h', '7025', 'L', 'g', '2251', 'S', 'j', '8281', '7793', 'd', 'I', 'e', '9405', 'O', 'i', 'N', '7397', 'a', '6859', '1395', 'L', 'S', '5171']

20, 10, 18, 9973, 21, 23, 4015, 7875, 7151, 6997, 2317, 8, 7025, 12, 7, 2251, 19, 10, 8281, 7793, 4, 9, 5, 9405, 15, 9, 14, 7397, 1, 6859, 1395, 12, 19, 5171