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: ['U', '4705', '7003', '439', 'F', '2055', '5399', '3323', 'L', '779', 'D', '4513', '2787', '791', '3225', '3431', 'f', 'D', '9949', '7491', '8651', 'N', '2847', '215', '4319', '6895', '8651', '9153', 's', 'v', 'U', 'y', '5459', 'Z', '5069']

21, 4705, 7003, 439, 6, 2055, 5399, 3323, 12, 779, 4, 4513, 2787, 791, 3225, 3431, 6, 4, 9949, 7491, 8651, 14, 2847, 215, 4319, 6895, 8651, 9153, 19, 22, 21, 25, 5459, 26, 5069