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: ['p', 'i', '1783', '3503', '499', '9345', '4711', '979', 'R', 'Y', '1357', '8515', '6081', 'Q', 'D', 'P', 'P', '349', 'P', 'T']

16, 9, 1783, 3503, 499, 9345, 4711, 979, 18, 25, 1357, 8515, 6081, 17, 4, 16, 16, 349, 16, 20