1987. What character can be added to both of these characters to give other characters? 止_ -> _却

止  SHI, to(meru), to(maru) - stop

却  KYAKU - pull back, withdraw

Add 月:止+月 月+却   

月  GETSU, GATSU, tsuki - moon, month

肯  KOU - agree, consent

脚  KYAKU, KYA, ashi - leg