Number Choosing Contest.

38, 39, 41, 42, 43

38: breaks YZ & 1, 2, 3 and 4.
39: breaks YZ & 1, 2, 3, 4 and 5.
41: breaks YZ & 1, 2, 3, 4 and 5.
42: breaks YZ & 2, 3, 4 and 5.
43: breaks YZ & 1, 2, 3 and 4.