_=int(input())
for __ in range(_):
    a,b,c,x,y,d=map(int,input().split())
    mn=10**5000
    t=a
    if(d//x>=1):
        t=d%x*b
    mn=min(mn,d//x*a+min(t,a))
    t=0
    if(d%(x+y)<=x):
        t=a
    else:
        t=a+b*(d%(x+y)-x)
    tt=t
    if(d//(x+y)>0):
        tt=c*(d%(x+y))
    mn=min(mn,d//(x+y)*(b*y+a)+min(t,tt))
    if(d//(x+y)>0):
        t=a+b*y+(d-x-y)*c
    mn=min(mn,t)
    print(mn)

answer.code:1:1: error: ‘_’ does not name a type
    1 | _=int(input())
      | ^