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', 'm', 'E', 'r', '7277', '1931', 'a', '5549', 'H', 'W', '9667', '1007', '6571', 'P', 'c', '2171', 'R']

16, 13, 5, 18, 7277, 1931, 1, 5549, 8, 23, 9667, 1007, 6571, 16, 3, 2171, 18