A random variable x can take on values of 1, 2, 3, 4, and 5. A random variable y can take on values of 2, 4, and 6. If a random sequence of x is {2, 4, 3, 1, 5, 4, 3, 4} and the corresponding sequence of y is {4, 2, 6, 6, 2, 2, 6, 2}, what is the transformation rule?