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: ['c', 'Q', 'U', '1817', 'T', '5131', 'Z', '8437', 'x', 'e', 'v', '8141', 'd', 't']

3, 17, 21, 1817, 20, 5131, 26, 8437, 24, 5, 22, 8141, 4, 20