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: ['9121', 'x', '3517', '3797', '9865', 'P', '2171', 'a', 'm', 'J', 'f', 'p', '5385']

9121, 24, 3517, 3797, 9865, 16, 2171, 1, 13, 10, 6, 16, 5385