Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 3 monsters Once per turn: You can detach 1 Xyz Material from this card; all face-up monsters you currently control gain 300 ATK.
--No.20 蟻岩土ブリリアント
--Number 20: Giga-Brilliant
local s,id=GetID()
function s.initial_effect(c)
	--xyz summon
	Xyz.AddProcedure(c,nil,3,2)
	c:EnableReviveLimit()
	--attack up
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_ATKCHANGE)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetCountLimit(1)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCost(Cost.DetachFromSelf(1))
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
s.xyz_number=20
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(Card.IsFaceup,tp,LOCATION_MZONE,0,nil)
	local tc=g:GetFirst()
	for tc in aux.Next(g) do
		local e1=Effect.CreateEffect(e:GetHandler())
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_UPDATE_ATTACK)
		e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE)
		e1:SetValue(300)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD)
		tc:RegisterEffect(e1)
	end
end