def calc(D, A, B, C, X, Y):
    if D <= X:
        return A
    elif D <= X + Y:
        return A + B * (D - X)
    else:
        return A + B * Y + C * (D - X - Y)


for q in range(int(input())):
    A, B, C, X, Y, D = map(int, input().split())
    # 1台だけ使う場合
    base = calc(D, A, B, C, X, Y)
    res = base
    # ABを出来るだけ使う場合
    res = min(res, D // (X + Y) * (A + B * Y) + calc(D % (X + Y), A, B, C, X, Y))
    # Aを使ってお得になる場合
    c_rem = max(0, D - X - Y)
    b_rem = Y
    res_A = base
    if C * X > A:
        res_A -= (C * X - A) * (c_rem // X)
        c_rem %= X
    if c_rem < X and C * c_rem + B * (X - c_rem) > A:
        res_A -= C * c_rem + B * (X - c_rem) - A
        b_rem -= X - c_rem
        c_rem = 0
    if c_rem == 0:
        if B * X > A:
            res_A -= (B * X - A) * (b_rem // X)
            b_rem %= X
        if b_rem < X and B * b_rem > A:
            res_A -= B * b_rem - A
    res = min(res, res_A)
    # ABを使ってお得になる場合
    c_rem = max(0, D - X - Y)
    b_rem = Y
    res_AB = base
    if C * (X+Y) > A + B * Y:
        res_AB -= (C * (X+Y) - A - B * Y) * (c_rem // (X+Y))
        c_rem %= X+Y
    res = min(res, res_AB)
    # output
    print(res)