EnemyTowers

As a serious strategy-games player, you often need to find the best strategy for destroying your opponents' guard towers. You are currently preparing to play a game where your opponent has numWodT wooden towers and numStoT stone towers. Each tower has hpT hit points, and once a tower loses all its hit points, it is destroyed. You have myUnits soldiers. Because different weapons are required to destroy different types of towers, you must divide your soldiers into two groups. The first group will attack only wooden towers and the second group will attack only stone towers. You can divide your soldiers up however you like, but once the game begins, you are not allowed to re-assign them to different groups.

In each round of attacks, the following happens:
1. Each soldier from the first group attacks a single wooden tower and inflicts 1 hit point of damage. You can pick the tower independently for each soldier.
2. Each solider from the second group attacks a single stone tower and inflicts 1 hit point of damage. You can pick the tower independently for each soldier.
3. Your opponent attacks. The wooden towers will kill w*attackT of your soldiers from the first group, where w is the number of remaining wooden towers, and the stone towers will kill s*attackT of your soldiers from the second group, where s is the number of remaining stone towers.

Return the minimum number of rounds required to destroy all the towers, or return -1 if it is impossible.