Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Gain 500 Life Points. If this card was activated as Chain Link 2 or 3, add this card to the Deck and shuffle it. If this card was activated as Chain Link 4 or higher, return this card to the hand.
--チェーン・ヒーリング
--Chain Healing
local s,id=GetID()
function s.initial_effect(c)
	--recover
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCategory(CATEGORY_RECOVER)
	e1:SetProperty(EFFECT_FLAG_PLAYER_TARGET)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.rectg)
	e1:SetOperation(s.recop)
	c:RegisterEffect(e1)
end
function s.rectg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.SetTargetPlayer(tp)
	Duel.SetTargetParam(500)
	Duel.SetOperationInfo(0,CATEGORY_RECOVER,nil,0,tp,500)
end
function s.recop(e,tp,eg,ep,ev,re,r,rp)
	local p,d=Duel.GetChainInfo(0,CHAININFO_TARGET_PLAYER,CHAININFO_TARGET_PARAM)
	Duel.Recover(p,d,REASON_EFFECT)
	local c=e:GetHandler()
	if not c:IsRelateToEffect(e) or not e:IsHasType(EFFECT_TYPE_ACTIVATE) then return end
	local ct=Duel.GetCurrentChain()
	if ct>3 then
		c:CancelToGrave()
		Duel.SendtoHand(c,nil,REASON_EFFECT)
	elseif ct>1 then
		c:CancelToGrave()
		Duel.SendtoDeck(c,nil,SEQ_DECKSHUFFLE,REASON_EFFECT)
	end
end