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: ['1873', 'V', '6513', '7435', 'V', 's', 'L', '7329', '7065', '6807', '7105', 'p', '6511', 't', 'm', 'm', '523', '9203', 'g', 'm', '4759', 'U', 'u', 'M', 'N', '2407', 'P', 'd', 'e', 'H', '5431']

1873, 22, 6513, 7435, 22, 19, 12, 7329, 7065, 6807, 7105, 16, 6511, 20, 13, 13, 523, 9203, 7, 13, 4759, 21, 21, 13, 14, 2407, 16, 4, 5, 8, 5431