input: Write a python function to find the two smallest numbers in an array.
  assert findSmallest([4, 7, 2, 9, 1.5, 8]) == (1.5, 2)
  assert findSmallest([10, 20, 5, 3, 15]) == (3, 5)
  assert findSmallest([6, 5, 4, 3, 2, 1]) == (1, 2)
output: def findSmallest(arr):
      if len(arr) < 2:
          return None
      smallest = float('inf')
      second_smallest = float('inf')
      for num in arr:
          if num < smallest:
              second_smallest = smallest
              smallest = num
          elif num < second_smallest:
              second_smallest = num
      return (smallest, second_smallest)