Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
If you Ritual Summon exactly 1 WATER Ritual Monster with a card effect that requires use of monsters, this card can be used as the entire requirement. You can discard this card; add 1 "Gishki" Ritual Spell Card from your Deck to your hand.
--シャドウ・リチュア
--Gishki Shadow
local s,id=GetID()
function s.initial_effect(c)
	--search
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_TOHAND+CATEGORY_SEARCH)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_HAND)
	e1:SetCost(Cost.SelfDiscard)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
	--ritual level
	Ritual.AddWholeLevelTribute(c,aux.FilterBoolFunction(Card.IsAttribute,ATTRIBUTE_WATER))
end
s.listed_series={SET_GISHKI}
function s.filter(c)
	return c:IsSetCard(SET_GISHKI) and c:IsRitualSpell() and c:IsAbleToHand()
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk,chkc)
	if chk==0 then return Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_DECK,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_TOHAND,nil,1,tp,LOCATION_DECK)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp,chk)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_ATOHAND)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_DECK,0,1,1,nil)
	if #g>0 then
		Duel.SendtoHand(g,nil,REASON_EFFECT)
		Duel.ConfirmCards(1-tp,g)
	end
end