input: Write a python function to calculate the sum of a list of numbers.
  assert find_sum([1, 2, 3, 4, 5])==15
  assert find_sum([10, 20, 30, 40, 50])==150
  assert find_sum([5, 5, 5, 5, 5])==25
output: def find_sum(numbers):
      return sum(numbers)