i find one solution that is similar
% }9 F! ^0 j' ~! u! A# f% u6 Bbut i can't specify the heavier one is abnormal or the lighter one is abnormal when the case that has only two balls left....tvb now,tvbnow,bttvb/ k, m' q0 `) V6 y" `( T" o
maybe there is a better one, let me see sin |