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: ['553', '3821', 'k', 'a', 'O', 'd', '2867', '6687', '5523', 'g', 'E', '1819', '3527', '9417', '4035', '4491', 'c', '7591', 'O', 'n', '2981', '7831', 'W', 'Z', 'b', '5057', 'V', 't', 'k', 'O', 'd', 'R', 'w', '5281', 'P', '4697', 'J', '7237']

553, 3821, 11, 1, 15, 4, 2867, 6687, 5523, 7, 5, 1819, 3527, 9417, 4035, 4491, 3, 7591, 15, 14, 2981, 7831, 23, 26, 2, 5057, 22, 20, 11, 15, 4, 18, 23, 5281, 16, 4697, 10, 7237