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: ['6723', 'd', 'R', '4401', 'g', 'x', '3071', '1989', 'i', 'O', '1083', '4187', '2099', 'P', 'N', '5007', '5329', '5337', 'c', 'F', 'C', 'A']

6723, 4, 18, 4401, 7, 24, 3071, 1989, 9, 15, 1083, 4187, 2099, 16, 14, 5007, 5329, 5337, 3, 6, 3, 1