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: ['2479', 'z', '7031', '2973', '1537', 'Z', 'm', 'G', 'L', '5993', '8747', '1307', '6243', 'S', 'f', '1941']

2479, 26, 7031, 2973, 1537, 26, 13, 7, 12, 5993, 8747, 1307, 6243, 19, 6, 1941