def calc(n, a, b, c, x, y):
    if n == 0:
        return 0
    ans = a
    n -= x
    if n <= 0:
        return ans
    t = min(n, y)
    ans += t * b
    n -= t
    if n <= 0:
        return ans
    return ans + n * c

T = int(input())
for i in range(T):
    a, b, c, x, y, d = map(int, input().split())
    if d <= x:
        print(a)
        continue
    if a == min([a, b * x, c * x]):
        t = d // x
        print((t - 1) * a + min(a * 2, calc(d - (t - 1) * x, a, b, c, x, y)))
        continue
    if (b == min([a, b * x, c * x])):
        t = d // (x + y)
        print(t * (a + b * y) + calc(d - t * (x + y), a, b, c, x, y))
        continue
    t = d // x
    print(min([calc(d, a, b, c, x, y), (t - 1) * a + min(a * 2, calc(d - (t - 1) * x, a, b, c, x, y))]))