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: ['2957', 'K', 'v', 't', '6647', '929', 'm', '7857', 'w', '8509', '453']

2957, 11, 22, 20, 6647, 929, 13, 7857, 23, 8509, 453