input: Write a function to check if an element exists within a given list of integers. If the element exists in the list, return True; otherwise, return False. If the list is empty, return False.
  assert element_exists(5, [3, 4, 5, 1, 2])==True
  assert element_exists(10, [3, 4, 5, 1, 2])==False
  assert element_exists(1, [])==False
output: def element_exists(element, lst):
      if not lst:
          return False
      return element in lst