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: ['H', '2617', '753', '9675', 'u', '2153', 'N', '3657', 'F', 'R', '4317', 'U', 'A', '1649', 'e', 'e', '4267', 'R', '7431', '6015', '849', 'L', '1951']

8, 2617, 753, 9675, 21, 2153, 14, 3657, 6, 18, 4317, 21, 1, 1649, 5, 5, 4267, 18, 7431, 6015, 849, 12, 1951