t = int(input())
while t > 0:
    t -= 1
    a, b, c, x, y, d = map(int, input().split())
    ans = (d+x-1)//x * a
    if d >= x+y:
        ans = min(ans, a+b*y+(d-x-y)*c)
        d2 = (d-(x+y))//x
        d3 = d-d2*x
        ans = min(ans, d2*a+a+b*y+(d3-x-y)*c)
        d4 = (d-(x+y))//(x+y)
        d5 = d-d4*(x+y)
        ans = min(ans, d4 * (a+b*y) + a + b * y + (d5 - x - y) * c)
    if d >= x:
        k = d//x
        if d <= k*(x+y):
            d6 = d-k*x
            ans = min(ans, k*a+d6*b)
        k2 = (d+x+y-1)//(x+y)
        if d >= k2*x:
            d7 = d-k2*x
            ans = min(ans, k2*a+d7*b)
        k2 -= 1
        if d >= k2*x:
            d7 = d-k2*x
            ans = min(ans, k2*a+d7*b)
    print(ans)