P, Q, R, S, T, U, V, W and X are nine shops. P is 6 km west of Q. S is in the middle of P and Q. U is 3 km north of S. R is 6 km east of Q. T is in the middle of Q and R. V is 3 km south of T. W is 4 km west of V. X is 6 km north of W.

What is the position of U with respect to X?