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: ['4237', '7981', '3559', '7267', 'u', 'h', '4523', 'H', 'z', 'S', '5663', '953', 'U', '8603', 'i', 'M', 'B', 'f', '8085', 'P', '5069', 'Q', 'L', '9409', '7025', '251', '3785', 'k', 'S', '9685', 'l', 'j', '4409', '7853', 'Q', '2603', '7421', '5159', 'E', '6789']

4237, 7981, 3559, 7267, 21, 8, 4523, 8, 26, 19, 5663, 953, 21, 8603, 9, 13, 2, 6, 8085, 16, 5069, 17, 12, 9409, 7025, 251, 3785, 11, 19, 9685, 12, 10, 4409, 7853, 17, 2603, 7421, 5159, 5, 6789