def solve():
    a,b,c,x,y,d=map(int,input().split())
    t1=(d+x-1)//x #全程A
    t2=t1-1 #前半程A，收尾b
    t3=(d+(x+y)-1)//(x+y)
    t4=t3-1    
    if(x>=d):
        return a
    elif(x+y>=d):
        return min(a*t1,a*t2+b*(d-t2*x),a+b*(d-x))
    else:
        v1=a/x #A均价
        v2=(a+b*y)/(x+y) #A+B均价
        v3=c #C均价
        #print(f"v1{v1} v2{v2} v3{v3}")
        if(v1==min(v1,v2,v3)):
            ans=t1*a
            ans1=t2*a+min(t2*y,d-t2*x)*b+(d-t2*x-min(t2*y,d-t2*x))*c
            ans2=t2*a+min(y,d-t2*x)*b+(d-t2*x-min(y,d-t2*x))*c
            return min(ans,ans1,ans2)
        elif(v2==min(v1,v2,v3)):
            if(d-t4*(x+y)>=x):
                ans=t3*a+(d-t3*x)*b
            t5=t4+((d-t4*(x+y)+x-1)//x)
            ans=min(ans,t5*a+t4*y*b-min(t4*y,(t5*x+t4*y-d))*b)
            ans=min(ans,t4*a+t4*y*b+(d-t4*(x+y))*c)
            return ans
        else:
            ans=t1*a
            ans1=t2*a+min(t2*y,d-t2*x)*b+(d-t2*x-min(t2*y,d-t2*x))*c
            ans2=a+y*b+(d-x-y)*c
            return min(ans,ans1,ans2)

if __name__ == "__main__":
    T=int(input())
    for _ in range(T):
        print(solve())