Points A(1,3)A(1,3)A(1,3), B(3,6)B(3,6)B(3,6), C(7,5)C(7,5)C(7,5) and D(5,k)D(5,k)D(5,k) are vertices in that order. Find k k\,k if ABCD ABCD\,ABCD is a parallelogram.