input: Write a function to calculate the sum of 15 integers provided as a list. The function should return the sum of the integers. If the list does not contain exactly 15 integers, the function should raise a ValueError indicating that the list does not have the required 15 integers.
  
  assert sum_nums([1, 5, 9, 0, 2, 4, 7, 8, 6, 10, 3, 11, 12, 13, 14])==105
  assert sum_nums([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15])==120
  assert sum_nums([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])==0
  assert sum_nums([-1, -2, -3, -4, -5, -6, -7, -8, -9, -10, -11, -12, -13, -14, -15])==-120
  assert sum_nums([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14])==105
  assert sum_nums([]) raises a ValueError with the message "The list does not have the required 15 integers"
output: def sum_nums(nums):
      if len(nums) != 15:
          raise ValueError("The list does not have the required 15 integers")
      return sum(nums)