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: ['6873', 's', '3661', 'l', 'c', '891', '8199', '9057', 'S', '7061', 'x', 's', '2193', 'N', 'f', 'p', '1959', 'O', '457', '9933', 'L', '3011', 'Q', 's', '9983', 'H', '795', 'N', 'M', 'q', 'S', 'O', 'S', '5833', 'w', '8783', 'o']

6873, 19, 3661, 12, 3, 891, 8199, 9057, 19, 7061, 24, 19, 2193, 14, 6, 16, 1959, 15, 457, 9933, 12, 3011, 17, 19, 9983, 8, 795, 14, 13, 17, 19, 15, 19, 5833, 23, 8783, 15