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: ['n', '8573', 'M', 'k', '1235', 'U', '5393', 'S', 'N', 'g', 'C', 'S', 'S', '3465', 'O', 'u', 'f', 'n', '3549', 'L', 'v', '5255', '183', '991', '8683', '5113', '7461', '2907', '1355', '8465', '9435', 'N', 'R']

14, 8573, 13, 11, 1235, 21, 5393, 19, 14, 7, 3, 19, 19, 3465, 15, 21, 6, 14, 3549, 12, 22, 5255, 183, 991, 8683, 5113, 7461, 2907, 1355, 8465, 9435, 14, 18