You are given two integer arrays of size 2: d = [d₁, d₂] and r = [r₁, r₂].

Two delivery drones are tasked with completing a specific number of deliveries. Drone i must complete d_i deliveries.

Each delivery takes exactly one hour and only one drone can make a delivery at any given hour.

Additionally, both drones require recharging at specific intervals during which they cannot make deliveries. Drone i must recharge every r_i hours (i.e. at hours that are multiples of r_i).

Return an integer denoting the minimum total time (in hours) required to complete all deliveries.

Example 1:

Input: d = [3,1], r = [2,3]

Output: 5

Explanation:

The first drone delivers at hours 1, 3, 5 (recharges at hours 2, 4).
The second drone delivers at hour 2 (recharges at hour 3).

Example 2:

Input: d = [1,3], r = [2,2]

Output: 7

Explanation:

The first drone delivers at hour 3 (recharges at hours 2, 4, 6).
The second drone delivers at hours 1, 5, 7 (recharges at hours 2, 4, 6).

Example 3:

Input: d = [2,1], r = [3,4]

Output: 3

Explanation:

The first drone delivers at hours 1, 2 (recharges at hour 3).
The second drone delivers at hour 3.

Constraints:

d = [d₁, d₂]
1 <= d_i <= 10⁹
r = [r₁, r₂]
2 <= r_i <= 3 * 10⁴