# [USACO07DEC]手链Charm Bracelet

## 题目描述

Bessie has gone to the mall's jewelry store and spies a charm bracelet. Of course, she'd like to fill it with the best charms possible from the N (1 ≤ N ≤ 3,402) available charms. Each charm i in the supplied list has a weight Wi (1 ≤ Wi ≤ 400), a 'desirability' factor Di (1 ≤ Di ≤ 100), and can be used at most once. Bessie can only support a charm bracelet whose weight is no more than M (1 ≤ M ≤ 12,880).
Given that weight limit as a constraint and a list of the charms with their weights and desirability rating, deduce the maximum possible sum of ratings.
有N件物品和一个容量为V的背包。第i件物品的重量是c[i]，价值是w[i]。求解将哪些物品装入背包可使这些物品的重量总和不超过背包容量，且价值总和最大。

## 输入输出格式

### 输入格式

\* Line 1: Two space-separated integers: N and M
\* Lines 2..N+1: Line i+1 describes charm i with two space-separated integers: Wi and Di
第一行：物品个数N和背包大小M
第二行至第N+1行：第i个物品的重量C[i]和价值W[i]

### 输出格式

\* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints
输出一行最大价值。

## 输入输出样例

### 输入样例 #1

```
4 6
1 4
2 6
3 12
2 7
```

### 输出样例 #1

`23`