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: ['a', 'P', '151', '877', 'N', 'l', 'S', 'M', '2931', 'm', 'F', 'X', '7041', '6933', '593', 'r', 'L', '8741', 'D', '5015', '7307', 'P', 'P', 'T', 'W', '6623', '2619', 't', '1835', '9165', '4211', '4175', '5111', '9523', '639', '9639', 'U', '8985', 'z', 'm']

1, 16, 151, 877, 14, 12, 19, 13, 2931, 13, 6, 24, 7041, 6933, 593, 18, 12, 8741, 4, 5015, 7307, 16, 16, 20, 23, 6623, 2619, 20, 1835, 9165, 4211, 4175, 5111, 9523, 639, 9639, 21, 8985, 26, 13