S:E17.88.
Y={1,6,7,8}
X={1,2,3,4,5}
S:E17.87.
sol1: A={0,1,2,3,4,5}
B{2,4,6}
sol2: A={0,2,4,5}
B={1,2,3,4,6}
sol3: A={1,2,4,5}
B={0,2,3,4,6}
sol4: A={2,3,4,5}
B={0,1,2,4,6}
sol5: A={0,1,2,4,5}
B={2,3,4,6}
sol6:A={0,2,3,4,5}
B={1,2,4,6}
sol7:A={1,2,3,4,5}
B=0,2,4,6}