t = int(input())
for i in range(t):
	a,b,c,x,y,d = map(int,input().split())
	if d <= x:
		print(a)
	else:
		k=d//x
		ans=k*a
		if k*x!=d:
			ans=ans+a #just use a's
		ost=d-k*x
		if ost <= y:
			ans=min(ans,k*a+ost*b)
		else:
			ans=min(ans,k*a+y*b+(ost-y)*c) #all remaining in 1
			if ost <= y*k:
				ans=min(ans,k*a+ost*b) #distribute
			else:
				ans=min(ans,k*a+y*k*b+(ost-y*k)*c) #distribute as much as possible
		if d <= x+y:
			ans=min(ans,a+(d-x)*b)
		else:
			k=d//(x+y)
			ost=d-k*(x+y)
			if ost==0:
				ans=min(ans,(a+y*b)*k)
			else:
				if ost<=x:
					ans=min(ans,(a+y*b)*k+a-min(x-ost,k*y)*b)
				else:
					ans=min(ans,(a+y*b)*k+a+(ost-x)*b)
			ans=min(ans,(a+y*b)*k+c*ost)
			ans=min(ans,a+y*b+(d-x-y)*c) #all in 1
		print(ans)

answer.code:10:35: error: stray ‘#’ in program
   10 |                         ans=ans+a #just use a's
      |                                   ^
answer.code:10:46: warning: missing terminating ' character
   10 |                         ans=ans+a #just use a's
      |                                              ^
answer.code:10:46: error: missing terminating ' character
   10 |                         ans=ans+a #just use a's
      |                                              ^~
answer.code:15:56: error: stray ‘#’ in program
   15 |                         ans=min(ans,k*a+y*b+(ost-y)*c) #all remaining in 1
      |                                                        ^
answer.code:17:56: error: stray ‘#’ in program
   17 |                                 ans=min(ans,k*a+ost*b) #distribute
      |                                                        ^
answer.code:19:68: error: stray ‘#’ in program
   19 |                                 ans=min(ans,k*a+y*k*b+(ost-y*k)*c) #distribute as much as possible
      |                                                                    ^
answer.code:33:54: error: stray ‘#’ in program
   33 |                         ans=min(ans,a+y*b+(d-x-y)*c) #all in 1
      |                                                      ^
answer.code:1:1: error: ‘t’ does not name a type
    1 | t = int(input())
      | ^