input: Write a function to find the smallest number in a given list.
  def smallestNumber(nums):
      smallest = nums[0]
      for i in range(1, len(nums)):
          if nums[i] < smallest:
              smallest = nums[i]
      return smallest
  
  assert smallestNumber([4, 5, 6, 7, 8])==4
  assert smallestNumber([10, 20, 1, 30, 40])==1
  assert smallestNumber([-5, -2, -10, -1])==-10
  assert smallestNumber([1])==1
  assert smallestNumber([0, 0, 0, 0])==0
output: def smallestNumber(nums):
      smallest = nums[0]
      for i in range(1, len(nums)):
          if nums[i] < smallest:
              smallest = nums[i]
      return smallest