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: ['W', 'f', 'l', '3517', 's', 'c', 'b', 'D', 'B', '7745', '8769', '9987', 'U', '3187', '4925', 'A', 'B', '9003', '2947', 'M', '5651', 'A', 'W', '7375', '7309', '1701', '1059', 'l', 'G', '9137', '3147', 'y', 's', '6211', '3417', 'k', 'o', 'z', 'M']

23, 6, 12, 3517, 19, 3, 2, 4, 2, 7745, 8769, 9987, 21, 3187, 4925, 1, 2, 9003, 2947, 13, 5651, 1, 23, 7375, 7309, 1701, 1059, 12, 7, 9137, 3147, 25, 19, 6211, 3417, 11, 15, 26, 13