Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Must be Special Summoned with "Mask Change". Gains 100 ATK for each "HERO" monster in your GY.
--M・HERO 剛火
--Masked HERO Goka
local s,id=GetID()
function s.initial_effect(c)
	c:EnableReviveLimit()
	--Special summon condition
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetCode(EFFECT_SPSUMMON_CONDITION)
	e1:SetValue(aux.FALSE)
	c:RegisterEffect(e1)
	--ATK increase
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetProperty(EFFECT_FLAG_SINGLE_RANGE)
	e2:SetRange(LOCATION_MZONE)
	e2:SetCode(EFFECT_UPDATE_ATTACK)
	e2:SetValue(s.atkup)
	c:RegisterEffect(e2)
end
s.listed_series={SET_HERO}
function s.atkup(e,c)
	return Duel.GetMatchingGroupCount(Card.IsSetCard,c:GetControler(),LOCATION_GRAVE,0,nil,SET_HERO)*100
end