鷸蚌相爭，漁翁得利

鷸蚌相爭，漁翁得利|鹬蚌相争，渔翁得利 [yù bàng xiāng zhēng , yú wēng dé lì] ► lit. sandpiper and clam war together and the fisherman catches both (idiom); fig. neighbors who can't agree lose out to a third party