t = int(input())
for i in range(t):
    a, b, c, x, y, d = map(int, input().split())

    def cost(dis):
        if dis <= 0:
            return 0
        elif dis <= x:
            return a
        elif dis <= x + y:
            return a + (dis - x) * b
        else:
            return a + b * y + (dis - x - y) * c

    cx = d // x
    ans = cx * cost(x) + cost(d % x)
    if d % x <= cx * y:
        ans = min(ans, cx * cost(x) + d % x * b)
    else:
        ans = min(ans, cx * cost(x) + cx * y * b + (d % x - cx * y) * c)

    cxy = d // (x + y)
    ans = min(ans, cxy * cost(x + y) + cost(d % (x + y)))
    ans = min(ans, cxy * cost(x + y) + d % (x + y) * c)
    cxyp = (d + x + y - 1) // (x + y)
    ans = min(ans, cxyp * a + max(d - cxyp * x, 0) * b)

    print(ans)