Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Once per turn: You can Normal Summon 1 Level 4 LIGHT Thunder-Type monster from your hand, except "Mahunder", as an additional Normal Summon.
--OKaサンダー
--Mahunder
local s,id=GetID()
function s.initial_effect(c)
	--summon
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_SUMMON)
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetTarget(s.target)
	e1:SetOperation(s.operation)
	c:RegisterEffect(e1)
end
function s.filter(c)
	return c:IsRace(RACE_THUNDER) and c:IsAttribute(ATTRIBUTE_LIGHT) and c:GetLevel()==4
		and c:GetCode()~=id and c:IsSummonable(true,nil)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.GetLocationCount(tp,LOCATION_MZONE)>0
		and Duel.IsExistingMatchingCard(s.filter,tp,LOCATION_HAND,0,1,nil) end
	Duel.SetOperationInfo(0,CATEGORY_SUMMON,nil,1,0,0)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_SUMMON)
	local g=Duel.SelectMatchingCard(tp,s.filter,tp,LOCATION_HAND,0,1,1,nil)
	local tc=g:GetFirst()
	if tc then
		Duel.Summon(tp,tc,true,nil)
	end
end