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: ['Z', '515', 'W', '3435', 'S', 'd', 'j', 'S', '8769', 'C', 'V', 'f', 'C', '4825', '9171', '3749', '5699', 'j', 'h', '537']

26, 515, 23, 3435, 19, 4, 10, 19, 8769, 3, 22, 6, 3, 4825, 9171, 3749, 5699, 10, 8, 537