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: ['m', 'e', '7487', 'g', '1213', 'f', '9769', '5037', 'j', 'Z', '2333', 'G', 'c', 'c', '7231', '953', 'k', '7243', '5059', '6139', '1307', '2693', '1463', '8097', '1457', '4973', '3541', 'Y', '1917', 't', 'O', '7403']

13, 5, 7487, 7, 1213, 6, 9769, 5037, 10, 26, 2333, 7, 3, 3, 7231, 953, 11, 7243, 5059, 6139, 1307, 2693, 1463, 8097, 1457, 4973, 3541, 25, 1917, 20, 15, 7403