dé yú wàng quán
lit. catch fish then forget the trap (idiom, from Zhuangzi 莊子|庄子[Zhuang1 zi3]); fig. to take help for granted
得
dé
to obtain
鱼
yú
fish (CL:條|条[tiao2],尾[wei3])
忘
wàng
to forget
筌
quán
bamboo fish trap