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: ['2137', 'M', '5719', 'U', 'h', 'y', '6309', 'D', '9887', 'e', '1653', '8941', '9441', 'Y', 'u', 'K', 'A', 'x', 'B', 'n', 'K', '5837', 'W', 'n', '6309', 'o']

2137, 13, 5719, 21, 8, 25, 6309, 4, 9887, 5, 1653, 8941, 9441, 25, 21, 11, 1, 24, 2, 14, 11, 5837, 23, 14, 6309, 15