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', 'E', 'N', 'I', '5939', 'Z', '7849', 'B', 'Q', '3125', 't', 'x', 'h', '1603', '1671', '3811', 'g', '2559', '9861', 'a', '8507']

3, 5, 14, 9, 5939, 26, 7849, 2, 17, 3125, 20, 24, 8, 1603, 1671, 3811, 7, 2559, 9861, 1, 8507