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', 'C', 'I', '123', '803', '8265', 'r', '5627', 'D', 'U', '2945', 'f', 'N', '9371', '1987', '2873', '4511', 'O', 'i']

3, 3, 9, 123, 803, 8265, 18, 5627, 4, 21, 2945, 6, 14, 9371, 1987, 2873, 4511, 15, 9