input: Write a function to check if any integer appears more than once in a given list.
  assert check_duplicates(([1,2,3,4,5]))==False
  assert check_duplicates(([1,2,3,4,4]))==True
  assert check_duplicates([1,1,2,2,3,3,4,4,5])==True
output: def check_duplicates(lst):
      return len(lst) != len(set(lst))