def test_normal(self):
question = ['"3"', '"-2"']
assert -2 == answer(question)
def test_double_duplication(self):
question = ['"7"', '"7"', '"5"', '"5"', '"4"', '"2"']
assert 5 == answer(question)
def test_full_duplication(self):
question = ['"4"', '"4"', '"4"']
assert -1 == answer(question)
def test_blank_array(self):
assert -1 == answer([])
def test_some_duplication(self):
question = ['"5"', '"5"', '"4"', '"2"']
assert 4 == answer(question)