Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Destroy a number of face-up cards on the field equal to the number of face-up Attack Position "X-Saber" monsters you control.
--セイバー・スラッシュ
--Saber Slash
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetCategory(CATEGORY_DESTROY)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	e1:SetTarget(s.target)
	e1:SetOperation(s.activate)
	c:RegisterEffect(e1)
end
s.listed_series={SET_X_SABER}
function s.cfilter(c)
	return c:IsFaceup() and c:IsAttackPos() and c:IsSetCard(SET_X_SABER)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	local c=e:GetHandler()
	if chk==0 then
		local ct=Duel.GetMatchingGroupCount(s.cfilter,tp,LOCATION_MZONE,0,nil)
		e:SetLabel(ct)
		return Duel.IsExistingMatchingCard(aux.FaceupFilter(aux.TRUE),tp,LOCATION_ONFIELD,LOCATION_ONFIELD,ct,c)
	end
	local ct=e:GetLabel()
	local sg=Duel.GetMatchingGroup(aux.FaceupFilter(aux.TRUE),tp,LOCATION_ONFIELD,LOCATION_ONFIELD,c)
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,sg,ct,0,0)
end
function s.activate(e,tp,eg,ep,ev,re,r,rp)
	local ct=Duel.GetMatchingGroupCount(s.cfilter,tp,LOCATION_MZONE,0,nil)
	local g=Duel.GetMatchingGroup(aux.FaceupFilter(aux.TRUE),tp,LOCATION_ONFIELD,LOCATION_ONFIELD,e:GetHandler())
	if #g>=ct then
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_DESTROY)
		local sg=g:Select(tp,ct,ct,nil)
		Duel.HintSelection(sg)
		Duel.Destroy(sg,REASON_EFFECT)
	end
end