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: ['6517', 'k', '3845', 'j', '3273', '1137', '2059', '2139', '5487', 'u', '61', 'a', 'z', 'X', '4969', '7085', '5801']

6517, 11, 3845, 10, 3273, 1137, 2059, 2139, 5487, 21, 61, 1, 26, 24, 4969, 7085, 5801