gistfile1.txt

import math
def dataInput():
	(N,P,W,H)=(int(x) for x in raw_input().split())	
	initData=[int(x) for x in raw_input().split()]
	return N,P,W,H,initData
def getResult():
	N,P,W,H,initData=dataInput()
	max=1
	def getMax(max):	
		while True:
			
			sum=0
			for i in range(N):
				if int(W/max)==0:
					return max-1
				if int(H/max) ==0:
					return max-1
				else:
					sum=sum+int(math.ceil(initData[i]/(int(W/max))))*max		     
			temp=int(math.ceil(sum/int(H/max)))
			if temp <= P*H:
				max=max+1		
				continue
			if  temp> P*H: 
				return max-1
	return getMax(1)
	
while True:
	try:
		n = int(raw_input())
		result=[getResult() for x in range(n)]	
		for i in result:
			print i

	except EOFError:
		break