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: ['1435', 'W', '191', '3603', '2249', '5421', 'X', 'z', 'u', '4031', '8513', '8201', 'Z', '1807', 'u', 'X', 'F', 'c', 'D', 'W', 's']

1435, 23, 191, 3603, 2249, 5421, 24, 26, 21, 4031, 8513, 8201, 26, 1807, 21, 24, 6, 3, 4, 23, 19