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: ['6473', 'D', 'S', '9287', '7533', '2831', '6641', '2067', '6795', '8235', 'x', '8341', '3989', '2455', '1993', 'o', '3725', '7133', '9519', '5157', 't', '5597', '7583', 'J', 'p']

6473, 4, 19, 9287, 7533, 2831, 6641, 2067, 6795, 8235, 24, 8341, 3989, 2455, 1993, 15, 3725, 7133, 9519, 5157, 20, 5597, 7583, 10, 16