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: ['R', '143', 'h', 'K', 'N', 'p', '9865', 't', '5785', '9059', 'P', 'm', 'Q', 'q', '647', 'C', 'U', 'F', '6381', '725', 'C', '9003', '7703', '9171', 'U', 'l', 'o', 'c', '8761', '3529', 'i', '7239', 'P', 'w', '3191']

18, 143, 8, 11, 14, 16, 9865, 20, 5785, 9059, 16, 13, 17, 17, 647, 3, 21, 6, 6381, 725, 3, 9003, 7703, 9171, 21, 12, 15, 3, 8761, 3529, 9, 7239, 16, 23, 3191