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: ['p', 'l', '1487', '9703', 'U', 'x', 'B', '9689', 'I', 'I', 'T', '8433', 'A', 'C', '7753', 'h', 'c', 'V', '5097', 'x']

16, 12, 1487, 9703, 21, 24, 2, 9689, 9, 9, 20, 8433, 1, 3, 7753, 8, 3, 22, 5097, 24