Knapsack Problem

You have N kinds of items that you want to put them into a knapsack. Item i has value v_i and weight w_i.

You want to find a subset of items to put such that:

• The total value of the items is as large as possible.
• The items have combined weight at most W, that is capacity of the knapsack.
• You can select as many items as possible into a knapsack for each kind.

Find the maximum total value of items in the knapsack.

Input

N W
v1 w1
v2 w2
:
vN wN

The first line consists of the integers N and W. In the following lines, the value and weight of the i-th item are given.

Output

Print the maximum total values of the items in a line.

Constraints

• 1 ≤ N ≤ 100
• 1 ≤ v_i ≤ 1000
• 1 ≤ w_i ≤ 1000
• 1 ≤ W ≤ 10000

Sample Input 1

4 8
4 2
5 2
2 1
8 3

Sample Output 1

21

Sample Input 2

2 20
5 9
4 10

Sample Output 2

10

Sample Input 3

3 9
2 1
3 1
5 2

Sample Output 3

27

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