Problem:
Score : 400 points

Problem Statement

You have N items and a bag of strength W.
The i-th item has a weight of w_i and a value of v_i.

You will select some of the items and put them in the bag.
Here, the total weight of the selected items needs to be at most W.

Your objective is to maximize the total value of the selected items.

Constraints

1 ≤ N ≤ 100

1 ≤ W ≤ 10^9

1 ≤ w_i ≤ 10^9

For each i = 2,3,...,N, w_1 ≤ w_i ≤ w_1 + 3.

1 ≤ v_i ≤ 10^7

W, each w_i and v_i are integers.

Input

Input is given from Standard Input in the following format:

N W
w_1 v_1
w_2 v_2
:
w_N v_N

Output

Print the maximum possible total value of the selected items.

Sample Input 1

4 6
2 1
3 4
4 10
3 4

Sample Output 1

11

The first and third items should be selected.

Sample Input 2

4 6
2 1
3 7
4 10
3 6

Sample Output 2

13

The second and fourth items should be selected.

Sample Input 3

4 10
1 100
1 100
1 100
1 100

Sample Output 3

400

You can take everything.

Sample Input 4

4 1
10 100
10 100
10 100
10 100

Sample Output 4

0

You can take nothing.

Solution in Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        SimpleKnapsack solver = new SimpleKnapsack();
        solver.solve(1, in, out);
        out.close();
    }

    static class SimpleKnapsack {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            int n = in.nextInt();
            int w = in.nextInt();

            long[] weights = new long[n];
            long[] values = new long[n];
            for (int i = 0; i < n; i++) {
                long ww = Long.parseLong(in.next());
                long vv = Long.parseLong(in.next());
                weights[i] = ww;
                values[i] = vv;
            }

            long result = 0;
            for (int i = 0; i < (1 << n); i++) {
                long tmp = 0;
                long tmpv = 0;
                for (int j = 0; j < n; j++) {
                    if (((i >> j) & 1) == 1) {
                        if (tmp + weights[j] <= w) {
                            tmp += weights[j];
                            tmpv += values[j];
                        }
                    }
                }
                result = Math.max(result, tmpv);
            }
            out.println(result);
        }

    }
}