Problem:
Score : 100 points

Problem Statement

There are N items, numbered 1, 2, \ldots, N.
For each i (1 \leq i \leq N), Item i has a weight of w_i and a value of v_i.

Taro has decided to choose some of the N items and carry them home in a knapsack.
The capacity of the knapsack is W, which means that the sum of the weights of items taken must be at most W.

Find the maximum possible sum of the values of items that Taro takes home.

Constraints

All values in input are integers.

1 \leq N \leq 100

1 \leq W \leq 10^9

1 \leq w_i \leq W

1 \leq v_i \leq 10^3

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 sum of the values of items that Taro takes home.

Sample Input 1

3 8
3 30
4 50
5 60

Sample Output 1

90

Items 1 and 3 should be taken.
Then, the sum of the weights is 3 + 5 = 8, and the sum of the values is 30 + 60 = 90.

Sample Input 2

1 1000000000
1000000000 10

Sample Output 2

10

Sample Input 3

6 15
6 5
5 6
6 4
6 6
3 5
7 2

Sample Output 3

17

Items 2, 4 and 5 should be taken.
Then, the sum of the weights is 5 + 6 + 3 = 14, and the sum of the values is 6 + 6 + 5 = 17.

Solution in Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.math.BigDecimal;
import java.text.DecimalFormat;
import java.util.AbstractMap;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.Deque;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {

    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        MyInput in = new MyInput(inputStream);
        PrintWriter out = new PrintWriter(outputStream);

        Solver solver = new Solver(in, out);
        solver.solve();

        out.close();
    }

    // ======================================================================

    static class Solver {
    	MyInput in;
    	PrintWriter out;
        public Solver(MyInput in, PrintWriter out) {
        	this.in = in;
        	this.out = out;
        }
        
        //-----------------------------------------
    	int N, WW;
    	int[] w, v;
        long[][] dp;

        long calc(int now, int weight) {
        	if(now >= N)	return 0;
        	if(dp[now][weight] != -1)	return dp[now][weight];
        	long ans = calc(now+1, weight);
        	if(weight + w[now] <= WW) {
        		ans = Math.max(ans, calc(now+1, weight + w[now]) + v[now]);
        	}
        	return dp[now][weight] = ans;
        }
        public void solve() {
        	N = ni();
        	WW = ni();
        	w = new int[N];
        	v = new int[N];
        	for(int i=0; i < N; i++) {
        		w[i] = ni();
        		v[i] = ni();
        	}
        	dp = new long[N+10][WW+10];
        	for (int i = 0; i < N+10; i++) {
				for (int j = 0; j < WW+10; j++) {
					dp[i][j] = -1;
				}
			}
        	prn(calc(0,0));
        }
        // -----------------------------------------
        void prn(String s) {
        	out.println(s);
        }
        void prn(int i) {
        	out.println(i);
        }
        void prn(long i) {
        	out.println(i);
        }
        void prr(String s) {
        	out.print(s);
        }
        int ni() {
        	return in.nextInt();
        }
        long nl() {
        	return in.nextLong();
        }
        double nd() {
        	return in.nextDouble();
        }
        String ns() {
        	return in.nextString();
        }
        int[] ndi(int n) {
        	int[] ans = new int[n];
        	for(int i=0; i < n; i++) {
        		ans[i] = ni();
        	}
        	return ans;
        }
        long[] ndl(int n) {
        	long[] ans = new long[n];
        	for(int i=0; i < n; i++) {
        		ans[i] = nl();
        	}
        	return ans;
        }
        double[] ndd(int n) {
        	double[] ans = new double[n];
        	for(int i=0; i < n; i++) {
        		ans[i] = nd();
        	}
        	return ans;
        }
        String[] nds(int n) {
        	String[] ans = new String[n];
        	for(int i=0; i < n; i++) {
        		ans[i] = ns();
        	}
        	return ans;
        }
        int[][] nddi(int n, int m) {
        	int[][] ans = new int[n][m];
        	for(int i=0; i < n; i++) {
            	for(int j=0; j < m; j++) {
            		ans[i][j] = ni();
            	}
        	}
        	return ans;
        }
        long[][] nddl(int n, int m) {
        	long[][] ans = new long[n][m];
        	for(int i=0; i < n; i++) {
            	for(int j=0; j < m; j++) {
            		ans[i][j] = nl();
            	}
        	}
        	return ans;
        }
    }

    static class PP{
    	public int key, val;
    	public PP(int key, int val) {
    		this.key = key;
    		this.val = val;
    	}
		public int getKey() {
			return key;
		}
		public void setKey(int key) {
			this.key = key;
		}
		public int getVal() {
			return val;
		}
		public void setVal(int val) {
			this.val = val;
		}
    }
    static class PPL {
    	public long key, val;
    	public PPL(long key, long val) {
    		this.key = key;
    		this.val = val;
    	}
		public long getKey() {
			return key;
		}
		public void setKey(long key) {
			this.key = key;
		}
		public long getVal() {
			return val;
		}
		public void setVal(long val) {
			this.val = val;
		}
    }
    static class PPDL {
    	public long key;
    	public long[] val;
    	public PPDL(long key, long[] val) {
    		this.key = key;
    		this.val = val;
    	}
		public long getKey() {
			return key;
		}
		public void setKey(long key) {
			this.key = key;
		}
		public long[] getVal() {
			return val;
		}
		public void setVal(long[] val) {
			this.val = val;
		}
		public void dump(PrintWriter out) {
			out.print("key = " + key + "  val ");
			for(int i=0; i < val.length; i++) {
				out.print("[" + val[i] + "] ");
			}
			out.println("");
		}
    }
    // HashMap のキーに使う
    static final class PPKEY{
    	private final int key, val;
    	public PPKEY(int key, int val) {
    		this.key = key;
    		this.val = val;
    	}
		public int getKey() {
			return key;
		}
		public int getVal() {
			return val;
		}
	    @Override
	    public boolean equals(Object obj) {
	        if (obj instanceof PPKEY) {
	        	PPKEY dest = (PPKEY) obj;
	            return this.key == dest.key && this.val == dest.val;
	        } else {
	            return false;
	        }
	    }
	    @Override
	    public int hashCode() {
	        return Objects.hash(key, val);
	    }
    }
    // HashMap のキーに使う
    static final class PPLKEY{
    	private final long key, val;
    	public PPLKEY(long key, long val) {
    		this.key = key;
    		this.val = val;
    	}
		public long getKey() {
			return key;
		}
		public long getVal() {
			return val;
		}
	    @Override
	    public boolean equals(Object obj) {
	        if (obj instanceof PPKEY) {
	        	PPKEY dest = (PPKEY) obj;
	            return this.key == dest.key && this.val == dest.val;
	        } else {
	            return false;
	        }
	    }
	    @Override
	    public int hashCode() {
	        return Objects.hash(key, val);
	    }
    }
    // グラフのリンクリスト
    static class Graph {
        private Map<Integer, List<Integer>> data = new HashMap<Integer, List<Integer>>();
        void add(int key, int value) {
        	List<Integer> list = data.get(key);
        	if(list == null) {
        		list = new ArrayList<Integer>();
        		data.put(key, list);
        	}
        	list.add(value);
        }
        List<Integer> get(int key) {
        	return data.get(key);
        }
        Set<Integer> keySet() {
        	return data.keySet();
        }
        boolean contains(int key, int value) {
        	List<Integer> list = data.get(key);
        	if(list == null)	return false;
        	else 				return list.contains(value);
        }
        void dump(PrintWriter out) {
        	for(int key : data.keySet()) {
        		out.print(key + " : ");
        		for(int val : data.get(key)) {
        			out.print(val + " ");
        		}
        		out.println("");
        	}
        }
    }
    // 重さを持ったグラフのリンクリスト
    static class GraphWith {
        private Map<Integer, List<PP>> data = new HashMap<Integer, List<PP>>();
        void add(int key, PP p) {
        	List<PP> list = data.get(key);
        	if(list == null) {
        		list = new ArrayList<PP>();
        		data.put(key, list);
        	}
        	list.add(p);
        }
        List<PP> get(int key) {
        	return data.get(key);
        }
        // グラフの存在チェック（重さは関係しない）
        boolean contains(int key, int value) {
        	List<PP> list = data.get(key);
        	if(list == null)	return false;
        	boolean ans = false;
        	for(PP p : list) {
        		if(p.getKey() == value) {
        			ans = true;
        			break;
        		}
        	}
        	return ans;
        }
    }
    // グラフのリンクリスト(Long)
    static class GraphLong {
        private Map<Long, List<Long>> G = new HashMap<Long, List<Long>>();
        void add(long key, long value) {
        	List<Long> list = G.get(key);
        	if(list == null) {
        		list = new ArrayList<Long>();
        		G.put(key, list);
        	}
        	list.add(value);
        }
        List<Long> get(long key) {
        	return G.get(key);
        }
    }
    // 重さを持ったグラフのリンクリスト(Long)
    static class GraphLongWith {
        private Map<Long, List<PPL>> G = new HashMap<Long, List<PPL>>();
        void add(long key, PPL p) {
        	List<PPL> list = G.get(key);
        	if(list == null) {
        		list = new ArrayList<PPL>();
        		G.put(key, list);
        	}
        	list.add(p);
        }
        List<PPL> get(long key) {
        	return G.get(key);
        }
    }

    // ======================================================================
    static class Pair<K, V> extends AbstractMap.SimpleEntry<K, V> {
        /** serialVersionUID. */
        private static final long serialVersionUID = 6411527075103472113L;

        public Pair(final K key, final V value) {
            super(key, value);
        }
     }
    static class MyInput {
        private final BufferedReader in;
        private static int pos;
        private static int readLen;
        private static final char[] buffer = new char[1024 * 8];
        private static char[] str = new char[500 * 8 * 2];
        private static boolean[] isDigit = new boolean[256];
        private static boolean[] isSpace = new boolean[256];
        private static boolean[] isLineSep = new boolean[256];

        static {
            for (int i = 0; i < 10; i++) {
                isDigit['0' + i] = true;
            }
            isDigit['-'] = true;
            isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true;
            isLineSep['\r'] = isLineSep['\n'] = true;
        }

        public MyInput(InputStream is) {
            in = new BufferedReader(new InputStreamReader(is));
        }

        public int read() {
            if (pos >= readLen) {
                pos = 0;
                try {
                    readLen = in.read(buffer);
                } catch (IOException e) {
                    throw new RuntimeException();
                }
                if (readLen <= 0) {
                    throw new MyInput.EndOfFileRuntimeException();
                }
            }
            return buffer[pos++];
        }

        public int nextInt() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            int ret = 0;
            if (str[0] == '-') {
                i = 1;
            }
            for (; i < len; i++) ret = ret * 10 + str[i] - '0';
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }

        public long nextLong() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            long ret = 0L;
            if (str[0] == '-') {
                i = 1;
            }
            for (; i < len; i++) ret = ret * 10 + str[i] - '0';
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }

        public double nextDouble() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            double ret = 0;
            if (str[0] == '-') {
                i = 1;
            }
            int cnt = 0;
            for (; i < len; i++) {
            	if(str[i] == '.') {
            		cnt = 10;
            		continue;
            	}
            	if(cnt == 0) {
            		ret = ret * 10 + str[i] - '0';
            	} else {
            		ret = ret + ((double)(str[i] - '0') / cnt);
            		cnt *= 10;
            	}
            }
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }

       public String nextString() {
        	String ret = new String(nextDChar()).trim();
            return ret;
        }

        public char[] nextDChar() {
            int len = 0;
            len = reads(len, isSpace);
            char[] ret = new char[len + 1];
            for (int i=0; i < len; i++)		ret[i] = str[i];
            ret[len] = 0x00;
            return ret;
        }

        public char nextChar() {
            while (true) {
                final int c = read();
                if (!isSpace[c]) {
                    return (char) c;
                }
            }
        }

        int reads(int len, boolean[] accept) {
            try {
                while (true) {
                    final int c = read();
                    if (accept[c]) {
                        break;
                    }
                    if (str.length == len) {
                        char[] rep = new char[str.length * 3 / 2];
                        System.arraycopy(str, 0, rep, 0, str.length);
                        str = rep;
                    }
                    str[len++] = (char) c;
                }
            } catch (MyInput.EndOfFileRuntimeException e) {
            }
            return len;
        }

        static class EndOfFileRuntimeException extends RuntimeException {
        }
    }
}