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: ['6953', '9451', 'U', 'm', 'K', 'y', '6147', 'x', '5347', 'b', 'f', 'g', '6125', '3327', 'z', 'a', '2777', 'O', 'Z', 'J', 'i', '3805', 'c', '4761', 'P', '6331', '201', 'e', '345', 'r', 'c', 'p', 'j', '2791', '2557', '9313', '2865', 'S']

6953, 9451, 21, 13, 11, 25, 6147, 24, 5347, 2, 6, 7, 6125, 3327, 26, 1, 2777, 15, 26, 10, 9, 3805, 3, 4761, 16, 6331, 201, 5, 345, 18, 3, 16, 10, 2791, 2557, 9313, 2865, 19