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: ['6763', '2941', '9507', '9169', '4855', '9145', '4539', '7783', 'b', '547', 'U', 'L', 'i', 'G', 'd', 'x', '3237', '2281', 'J', 'M', '5149', 'p', '8637', 'b', '6723', '3007', 'U', 'T', '5705', '673', 'H', '6631', 'D', '7907', '7721', 'F']

6763, 2941, 9507, 9169, 4855, 9145, 4539, 7783, 2, 547, 21, 12, 9, 7, 4, 24, 3237, 2281, 10, 13, 5149, 16, 8637, 2, 6723, 3007, 21, 20, 5705, 673, 8, 6631, 4, 7907, 7721, 6