A (finite) sequence s_0, s_1, ..., s_{n - 1} of integers is called a happy sequence if each two consecutive elements have a common divisor which is greater than 1, i.e. if gcd(s_i, s_{i + 1}) > 1 for all i. In Python, the sequence can be represented by a list [s_0, s_1, ..., s_{n - 1}]. Write a functions is_happy(l) that will get a list l that contains integers. The function should return True if the list contains a happy sequence, and False otherwise.