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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using Yorukatsu018.Questions;
using Yorukatsu018.Extensions;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Yorukatsu018.Questions
{
    /// <summary>
    /// ARC073 B
    /// </summary>
    public class QuestionE : AtCoderQuestionBase
    {
        public override IEnumerable<object> Solve(TextReader inputStream)
        {
            var nw = inputStream.ReadIntArray();
            var n = nw[0];
            var w = nw[1];

            var items = new Item[n + 1];
            for (int i = 0; i < n; i++)
            {
                var wv = inputStream.ReadIntArray();
                items[i + 1] = new Item(wv[0], wv[1]);
            }

            var minWeight = items[1].Weight;
            items = items.Select(item => new Item(item.Weight - minWeight, item.Value)).ToArray();

            var dpMaxValue = Enumerable.Range(0, n + 1).Select(
                _=> Enumerable.Range(0, n + 1).Select(
                    __ => Enumerable.Repeat(0, (n + 1) * 3).ToArray()).ToArray()).ToArray();    // dp[i番目まで][j個選んで][重さがk]

            var totalWeightMax = 0;
            for (int i = 1; i <= n; i++)
            {
                totalWeightMax += items[i].Weight;
                for (int j = 0; j <= i; j++)
                {
                    for (int k = 0; k <= totalWeightMax; k++)
                    {
                        // 入れない
                        dpMaxValue[i][j][k] = dpMaxValue[i - 1][j][k];

                        if (j > 0 && k - items[i].Weight >= 0)
                        {
                            // 入れる
                            dpMaxValue[i][j][k] = Math.Max(dpMaxValue[i][j][k], dpMaxValue[i - 1][j - 1][k - items[i].Weight] + items[i].Value);
                        }
                    }
                }
            }

            var maxValue = 0;
            for (int j = 0; j < dpMaxValue[n].Length; j++)
            {
                for (int k = 0; k < dpMaxValue[n][j].Length; k++)
                {
                    if ((long)minWeight * j + k <= w)
                    {
                        maxValue = Math.Max(maxValue, dpMaxValue[n][j][k]);
                    }
                }
            }

            yield return maxValue;
        }
    }

    struct Item
    {
        public int Weight { get; }
        public int Value { get; }

        public Item(int weight, int value)
        {
            Weight = weight;
            Value = value;
        }

        public override string ToString() => $"Weight:{Weight}, Value:{Value}";
    }
}

namespace Yorukatsu018
{
    class Program
    {
        static void Main(string[] args)
        {
            IAtCoderQuestion question = new QuestionE();    // 問題に合わせて書き換え
            var answers = question.Solve(Console.In);
            foreach (var answer in answers)
            {
                Console.WriteLine(answer);
            }
        }
    }
}

#region Base Classes

namespace Yorukatsu018.Questions
{

    public interface IAtCoderQuestion
    {
        IEnumerable<object> Solve(string input);
        IEnumerable<object> Solve(TextReader inputStream);
    }

    public abstract class AtCoderQuestionBase : IAtCoderQuestion
    {
        public IEnumerable<object> Solve(string input)
        {
            var stream = new MemoryStream(Encoding.Unicode.GetBytes(input));
            var reader = new StreamReader(stream, Encoding.Unicode);

            return Solve(reader);
        }

        public abstract IEnumerable<object> Solve(TextReader inputStream);
    }

}

#endregion

#region Extensions

namespace Yorukatsu018.Extensions
{
    internal static class TextReaderExtensions
    {
        internal static int ReadInt(this TextReader reader) => int.Parse(ReadString(reader));
        internal static long ReadLong(this TextReader reader) => long.Parse(ReadString(reader));
        internal static double ReadDouble(this TextReader reader) => double.Parse(ReadString(reader));
        internal static string ReadString(this TextReader reader) => reader.ReadLine();

        internal static int[] ReadIntArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(int.Parse).ToArray();
        internal static long[] ReadLongArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(long.Parse).ToArray();
        internal static double[] ReadDoubleArray(this TextReader reader, char separator = ' ') => ReadStringArray(reader, separator).Select(double.Parse).ToArray();
        internal static string[] ReadStringArray(this TextReader reader, char separator = ' ') => reader.ReadLine().Split(separator);
    }
}

#endregion