# GeetCode Hub

There are 3n piles of coins of varying size, you and your friends will take piles of coins as follows:

• In each step, you will choose any 3 piles of coins (not necessarily consecutive).
• Of your choice, Alice will pick the pile with the maximum number of coins.
• You will pick the next pile with maximum number of coins.
• Your friend Bob will pick the last pile.
• Repeat until there are no more piles of coins.

Given an array of integers `piles` where `piles[i]` is the number of coins in the `ith` pile.

Return the maximum number of coins which you can have.

Example 1:

```Input: piles = [2,4,1,2,7,8]
Output: 9
Explanation: Choose the triplet (2, 7, 8), Alice Pick the pile with 8 coins, you the pile with 7 coins and Bob the last one.
Choose the triplet (1, 2, 4), Alice Pick the pile with 4 coins, you the pile with 2 coins and Bob the last one.
The maximum number of coins which you can have are: 7 + 2 = 9.
On the other hand if we choose this arrangement (1, 2, 8), (2, 4, 7) you only get 2 + 4 = 6 coins which is not optimal.
```

Example 2:

```Input: piles = [2,4,5]
Output: 4
```

Example 3:

```Input: piles = [9,8,7,6,5,1,2,3,4]
Output: 18
```

Constraints:

• `3 <= piles.length <= 10^5`
• `piles.length % 3 == 0`
• `1 <= piles[i] <= 10^4`

class Solution { public int maxCoins(int[] piles) { } }