劳心

劳心	láo xīn	to work with one's brains / to rack one's brains / to worry
劳	láo	(bound form) to toil; labor / (bound form) laborer / (bound form) meritorious deed / (bound form) fatigue / to put sb to the trouble (of doing sth) / to express one's appreciation (Taiwan pr. [lao4])
心	xīn	heart / mind / intention / center / core / CL:颗,个