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: ['4261', 'b', 'p', '3771', '7357', 'U', '7573', '1227', 'L', 'X', 'I', '9737', '9289', 'f', '4413', '5021', '9089', '5991', '2123', '6949', 'n', 'o', '8441', 'j', '9777', 'x', 'J', 'S', 'V', '503', 'C', '3295', '8379', 'd', '7075', 'C', '665', 'x']

4261, 2, 16, 3771, 7357, 21, 7573, 1227, 12, 24, 9, 9737, 9289, 6, 4413, 5021, 9089, 5991, 2123, 6949, 14, 15, 8441, 10, 9777, 24, 10, 19, 22, 503, 3, 3295, 8379, 4, 7075, 3, 665, 24