Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Cannot be destroyed by battle with a monster that has 2000 or more ATK. Gains 200 ATK for each "Naturia" monster in your GY.
--ナチュル・ドラゴンフライ
--Naturia Dragonfly
local s,id=GetID()
function s.initial_effect(c)
	--indes
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_INDESTRUCTABLE_BATTLE)
	e1:SetValue(s.indes)
	c:RegisterEffect(e1)
	--atkup
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCode(EFFECT_UPDATE_ATTACK)
	e1:SetValue(s.atkval)
	c:RegisterEffect(e1)
end
s.listed_series={SET_NATURIA}
function s.indes(e,c)
	return c:GetAttack()>=2000
end
function s.filter(c)
	return c:IsSetCard(SET_NATURIA) and c:IsMonster()
end
function s.atkval(e,c)
	return Duel.GetMatchingGroupCount(s.filter,c:GetControler(),LOCATION_GRAVE,0,nil)*200
end