3. Write a function (count_a) to count number of characters ‘a’ in a list of character.
3. Write a function (count_not_z) to count number of characters not equal to ‘z’ in a list of character.
3. Write a function (count_M) to count number of characters ‘M’ in a list of character.
4. Write a function (count_beyond_k) to counter number of characters after (not include) character ‘k’ in a list of number. (l, m, n, o, p, …, z, A, B, …, Z) are counted but character a, b, …, k are not counted.