def test_high(self):
        cases = [(10000, "만"), (11020, "만 천이십"), (25891, "이만 오천팔백구십일"),
                 (64237, "육만 사천이백삼십칠"), (241572, "이십사만 천오백칠십이"),
                 (100000000, "일억"), (5000500000000, "오조 오억")]
        for num, out in cases:
            self.assertEqual(n2k(num), out)