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: ['J', '4875', '9509', 'x', '5601', '8735', 'W', 'U', '3847', 'u', 'o', '6353', '655', '1903', 'k', 'M', 'a', 'p', '6599', '129', '8539', '5553', '8771', '3799', '8057', '4007', 'U', '4913', '8275', '5757', 'f', '1231', '7297', '4175', '7657', 'V', '8985', '9405', 'i', 'i']

10, 4875, 9509, 24, 5601, 8735, 23, 21, 3847, 21, 15, 6353, 655, 1903, 11, 13, 1, 16, 6599, 129, 8539, 5553, 8771, 3799, 8057, 4007, 21, 4913, 8275, 5757, 6, 1231, 7297, 4175, 7657, 22, 8985, 9405, 9, 9