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: ['5149', 'c', 'D', '3279', 'm', 'U', '1007', '9463', 'w', 'c', '9759', '345', '9557', 'n', 'o', '7555', 'm', 'q', 'f', '2881', '3715', '2603', '9633', 'I', 'L']

5149, 3, 4, 3279, 13, 21, 1007, 9463, 23, 3, 9759, 345, 9557, 14, 15, 7555, 13, 17, 6, 2881, 3715, 2603, 9633, 9, 12