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', 'P', 'o', '5175', 'T', '2517', 'R', '7033', '9557', 'B', '6057', '3967', 'J', 'C', 'M', '6273', '3929', 'N', 'J', '1037', '2459']

21, 16, 15, 5175, 20, 2517, 18, 7033, 9557, 2, 6057, 3967, 10, 3, 13, 6273, 3929, 14, 10, 1037, 2459