def test1(self):
a = '1'
s = Solution()
res = s.foo(a)
self.assertEqual(1, res)
def test6(self):
a = '654321'
s = Solution()
res = s.foo(a)
self.assertEqual(2, res)
def test4(self):
a = '1111'
s = Solution()
res = s.foo(a)
self.assertEqual(5, res)
def test5(self):
a = '0111'
s = Solution()
res = s.foo(a)
self.assertEqual(0, res)
def test3(self):
a = '2626'
s = Solution()
res = s.foo(a)
self.assertEqual(4, res)
