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', 'S', 'A', '7513', '1479', '6775', '5831', 'M', 't', 'z', '7539', 'y', 'k', '6729', '6141', 'q', '9449', '3877', '1061', 'Z', 'g', 'E', 'J', '669']

26, 19, 1, 7513, 1479, 6775, 5831, 13, 20, 26, 7539, 25, 11, 6729, 6141, 17, 9449, 3877, 1061, 26, 7, 5, 10, 669