You are playing a solitaire game with **three piles** of stones of sizes `a`

, `b`

, and `c`

respectively. Each turn you choose two **different non-empty **piles, take one stone from each, and add `1`

point to your score. The game stops when there are **fewer than two non-empty** piles (meaning there are no more available moves).

Given three integers `a`

, `b`

, and `c`

, return *the* *maximum* **score** you can get.

**Example 1:**

Input:a = 2, b = 4, c = 6Output:6Explanation:The starting state is (2, 4, 6). One optimal set of moves is: - Take from 1st and 3rd piles, state is now (1, 4, 5) - Take from 1st and 3rd piles, state is now (0, 4, 4) - Take from 2nd and 3rd piles, state is now (0, 3, 3) - Take from 2nd and 3rd piles, state is now (0, 2, 2) - Take from 2nd and 3rd piles, state is now (0, 1, 1) - Take from 2nd and 3rd piles, state is now (0, 0, 0) There are fewer than two non-empty piles, so the game ends. Total: 6 points.

**Example 2:**

Input:a = 4, b = 4, c = 6Output:7Explanation:The starting state is (4, 4, 6). One optimal set of moves is: - Take from 1st and 2nd piles, state is now (3, 3, 6) - Take from 1st and 3rd piles, state is now (2, 3, 5) - Take from 1st and 3rd piles, state is now (1, 3, 4) - Take from 1st and 3rd piles, state is now (0, 3, 3) - Take from 2nd and 3rd piles, state is now (0, 2, 2) - Take from 2nd and 3rd piles, state is now (0, 1, 1) - Take from 2nd and 3rd piles, state is now (0, 0, 0) There are fewer than two non-empty piles, so the game ends. Total: 7 points.

**Example 3:**

Input:a = 1, b = 8, c = 8Output:8Explanation:One optimal set of moves is to take from the 2nd and 3rd piles for 8 turns until they are empty. After that, there are fewer than two non-empty piles, so the game ends.

**Constraints:**

`1 <= a, b, c <= 10`

^{5}

```
struct Solution;
impl Solution {
fn maximum_score(a: i32, b: i32, c: i32) -> i32 {
let sum = a + b + c;
let min = a.max(b).max(c);
(sum / 2).min(sum - min)
}
}
#[test]
fn test() {
let a = 2;
let b = 4;
let c = 6;
let res = 6;
assert_eq!(Solution::maximum_score(a, b, c), res);
let a = 4;
let b = 4;
let c = 6;
let res = 7;
assert_eq!(Solution::maximum_score(a, b, c), res);
let a = 1;
let b = 8;
let c = 8;
let res = 8;
assert_eq!(Solution::maximum_score(a, b, c), res);
}
```