main :: IO ()
main = defaultMain [tests]
  where
    tests = testGroup "" [case_1, case_2, case_3, case_4_1, case_4_2, case_4_3, case_4_4]
main :: IO ()
main = defaultMain [tests]
  where
    tests = testGroup "" [case_1, case_2, case_3, case_4_1, case_4_2, case_4_3, case_4_4]
main = defaultMain [tests]
  where
    tests = testGroup "" [case_1, case_2, case_3, case_4_1, case_4_2, case_4_3, case_4_4]