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: ['3477', 'R', 'h', 'S', '4727', 'l', 'b', 'a', 'R', '1251', 'G', 'A', '5135', '9087', 'S', 'q', '6329', '5105', '1287']

3477, 18, 8, 19, 4727, 12, 2, 1, 18, 1251, 7, 1, 5135, 9087, 19, 17, 6329, 5105, 1287