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: ['R', '5923', '3957', 'b', '3169', '1975', 'S', 'z', 'S', 's', '9835', 'K', 's', '7267', 'J', 'a', '1157', 'o', 'z', 'J', 'j', '9885', 'Y', '7393', '5567', 'U', '7717', '4029', '75', 'I', 'k', '283']

18, 5923, 3957, 2, 3169, 1975, 19, 26, 19, 19, 9835, 11, 19, 7267, 10, 1, 1157, 15, 26, 10, 10, 9885, 25, 7393, 5567, 21, 7717, 4029, 75, 9, 11, 283