input: Write a python function to filter strings with length less than or equal to 15 from a list of strings.
  assert filter_strings(['good', 'very good', 'excellent', 'awesome', 'extraordinary']) == ['good', 'very good', 'excellent', 'awesome']
  assert filter_strings(['short', 'adequate', 'supercalifragilisticexpialidocious', 'brief']) == ['short', 'adequate', 'brief']
  assert filter_strings(['tiny', 'minuscule', 'huge', 'gargantuan', 'massive']) == ['tiny', 'huge']
output: def filter_strings(strings):
      return [s for s in strings if len(s) <= 15]