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: ['s', '9967', 'c', '5707', '9653', '687', 'd', '2207', 'u', 'J', 'P', 'c', 'E', 'D', 'G', '1107', '9613', 'K']

19, 9967, 3, 5707, 9653, 687, 4, 2207, 21, 10, 16, 3, 5, 4, 7, 1107, 9613, 11