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: ['W', 'a', 'Y', 'C', '3417', 'B', 'x', 'S', '103', '4835', '1541', '1013', 'g', '3749', '1617', '3845', 'x', 'u', '6505', '8311']

23, 1, 25, 3, 3417, 2, 24, 19, 103, 4835, 1541, 1013, 7, 3749, 1617, 3845, 24, 21, 6505, 8311