input: Write a python function to find the second largest number in a list.
  assert find_second_largest([10, 20, 30, 40, 50, 35]) == 40
  assert find_second_largest([1, 2, 3, 4, 5]) == 4
  assert find_second_largest([100, 90, 80, 70, 60]) == 90
output: def find_second_largest(nums):
      first = second = float('-inf')
      for num in nums:
          if num > first:
              second = first
              first = num
          elif first > num > second:
              second = num
      return second