import math
t=int(input())
def calc(a,b,c,x,y,d,t):
	res=a*t
	d-=x*t
	if d<=0:
		return res
	mi=min(d,y)
	d-=mi
	res+=b*mi
	res+=d*c
	return res
def calc2(a,b,c,x,y,d,t):
	res=(a+b*y)*t
	d-=(x+y)*t
	if d<=0:
		return res
	mi=min(d,x)
	d-=mi
	res+=a
	mi=min(d,y)
	d-=mi
	res+=mi*b
	res+=d*c;
	return res
for o in range(0,t):
	a,b,c,x,y,d=map(int,input().split())
	ans=calc(a,b,c,x,y,d,1)
	for sb in range(1,5):
		ans=min(ans,calc(a,b,c,x,y,d,sb))
		ans=min(ans,calc(a,b,c,x,y,d,sb-1))
	if (d+x-1)//x+1>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x+1))
	if (d+x-1)//x>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x))
	if (d+x-1)//x-1>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-1))
	if (d+x-1)//x-2>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-2))
	if (d+x-1)//x-3>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1)//x-3))
	if (d+x-1-y)//x>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x))
	if (d+x-1-y)//x+1>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x+1))
	if (d+x-1-y)//x-1>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-1))
	if (d+x-1-y)//x-2>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-2))
	if (d+x-1-y)//x-3>0:
		ans=min(ans,calc(a,b,c,x,y,d,(d+x-1-y)//x-3))
	if (d+x+y-1)//(x+y)+1>=0:
		ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)+1))
	if (d+x+y-1)//(x+y)>=0:
		ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)))
	if (d+x+y-1)//(x+y)-1>=0:
		ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-1))
	if (d+x+y-1)//(x+y)-2>=0:
		ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-2))
	if (d+x+y-1)//(x+y)-3>=0:
		ans=min(ans,calc2(a,b,c,x,y,d,(d+x+y-1)//(x+y)-3))
	g=(d+x+y-1)//(x+y)
	if x*g<=d:
		ans=min(ans,g*a+(d-x*g)*b)
	print(ans)