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', 'E', '3147', 'q', 'o', 'J', '3621', '1751', '7785', '7879', 'c', 'e', '5103', '9863', 't', '6441', '9981', 'j', 'L', 'C']

19, 5, 3147, 17, 15, 10, 3621, 1751, 7785, 7879, 3, 5, 5103, 9863, 20, 6441, 9981, 10, 12, 3