inf = float('inf')

import sys
input = sys.stdin.readline

T = int(input())

for _ in range(T):
	A,B,C,X,Y,D = map(int, input().split())

	ans = inf

	#all A
	res = ((D+X-1)//X) * A
	ans = min(ans, res)

	#X, X, .. (A,B,C)
	cnt = D//X
	res = cnt*A
	if cnt > 0:
		rem = D - cnt*X
		if rem <= Y:
			res += B*rem
		else:
			res += B*Y
			rem -= Y
			res += C*rem
		ans = min(ans, res)

	#no use C
	Cx = D//X
	R = D%X
	Cy = (R+Y-1)//Y
	if Cx >= Cy:
		res = Cx*A + Cy*B
		ans = min(ans, res)

	#(X+Y), (X+Y), ... (A,B)
	Z = X+Y
	P = A + Y*B
	cnt = D//Z
	rem = D%Z
	res = cnt*P
	if rem <= X:
		res += A
	else:
		res += A
		res += (rem-X) * B
	ans = min(ans, res)

	#(X+Y), ... (A,B,C)
	if cnt > 0:
		res = cnt*P
		res += rem*C
		ans = min(ans, res)

	#all (A,B,C)
	if D>=Z:
		res = P
		rem = D-Z
		res += rem*C
		ans = min(ans, res)
	
	print(ans)