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
    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)/(x+y) #A+B均价
        v3=c #C均价
        #print(f"v1{v1} v2{v2} v3{v3}")
        if(v3==min(v1,v2,v3)):
            ans1=min(a+b*y+c*(d-x-y),a*t1)
            if(t2*(x+y)>=d):#t2组x+y中能到达终点
                ans2=a*t2+b*(d-t2*x)
            else:
                ans2=(a+b)*t2+c*(d-t2*(x+y))
            return min(ans1,ans2)
        elif(v2==min(v1,v2,v3)):
            t3=(d+(x+y)-1)//(x+y)
            t4=t3-1
            t5=((d-t4*(x+y))+x-1)//x
            d1=t4*y
            d2=t4*(x+y)+x*t5-d
            ans1=min(a*t4+b*t4*y+c*(d-t4*(x+y)), a*t4+b*t4*y+a*t5-b*min(d1,d2))
            if (d-t4*(x+y)>x):
                ans1=min(ans1,a*t4+b*t4*y+a+b*(d-t4*(x+y)-x))
            return ans1
        else:
            ans1=a*t1
            if(d-x*t2-y>0):
                ans1=min(ans1,a*t2+b+c*(d-x*t2-y))
            if((x+y)*t2>=d):
                ans1=min(ans1,a*t2+b*(d-t2*x))
            else:
                ans1=min(ans1,a*t2+b*t2*y+c*(d-(x+y)*t2))
            return ans1

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