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