input: Write a python function to find the second largest number in a list.
  assert findSecondLargest([45, 81, 90, 102, 24, 76]) == 90
  assert findSecondLargest([10, 20, 30, 40, 50]) == 40
  assert findSecondLargest([5, 5, 5, 5, 5, 5]) == -10000
output: def findSecondLargest(nums):
      first = second = float('-inf')
      for num in nums:
          if num > first:
              second = first
              first = num
          elif first > num > second:
              second = num
      return second if second != float('-inf') else -10000