import sys
sys.set_int_max_str_digits(10**7)

T=int(input())
for t in range(T):
    A,B,C,X,Y,D=map(int,input().split())
        #全部A
    ans=(D+X-1)//X*A
    #1台
    DD=D
    cost=0
    d=min(DD,X)
    cost+=A
    DD-=d
    d=min(DD,Y)
    cost+=d*B
    DD-=d
    cost+=DD*C
    ans=min(ans,cost)

    #ABAB+Cで調整
    cnt=D//(X+Y)
    if cnt>=1:
        ans=min(ans,cnt*(A+B*Y)+C*(D-cnt*(X+Y)))
    
    #ABAB+Aで調整
    cnt=(D+X+Y-1)//(X+Y)
    ans=min(ans,cnt*A+max(0,D-cnt*X)*B)

    #AAA+最後でBCCCCCC
    cnt=D//X
    if cnt>=1:
        cost=cnt*A
        DD=D-cnt*X
        d=min(DD,Y)
        DD-=d
        cost+=d*B
        cost+=DD*C
        ans=min(ans,cost)

    #AAA+最後でBBBBBBCCC
    cnt=D//X
    if cnt>=1:
        cost=cnt*A
        DD=D-cnt*X
        d=min(DD,Y*cnt)
        DD-=d
        cost+=d*B
        cost+=DD*C
        ans=min(ans,cost)
    print(ans)