2561. What character can be added to both of these characters to give other characters? 加_ -> _易

加  KA, kuwa(eru), kuwa(waru) - add, append, join, take part

易  EKI, I , yasa(shii), ya(sui) - easy, divination

Add 貝:加+貝 貝+易   

貝  KAI - shellfish

賀  GA - congratulations, felicitations

賜  SHI, tamawa(ru) - grant, bestow, confer