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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.awt.*;
import java.io.*;

import java.math.BigInteger;
import java.util.*;

public class Main{


    static Long[][] memo;
    static int n,W;
    static long OO = (long) 1e10;
    static int[] w , val;

    static long dp(int idx , int v)
    {
        if(idx == n) return v == 0 ? 0 : OO;
        if(memo[idx][v] != null) return  memo[idx][v];

        long ans =  dp(idx + 1 , v);

        if(val[idx] <= v) {
            long tmp = w[idx] + dp(idx + 1, v - val[idx]);
            ans = Math.min(ans, tmp);
        }
        return memo[idx][v] = ans;
    }


    static int solve(int value)
    {
        for (int v = value; v >= 0 ; v--)
        {
            if (dp(0, v) <= W)
                return v;
        }
        return 0;
    }


    public static void main(String[] args) throws Exception {

        Scanner sc = new Scanner(System.in);
        PrintWriter pw = new PrintWriter(System.out);

        n = sc.nextInt();
        W = sc.nextInt();

        w = new int[n];
        val = new int[n];
        int value = 0;
        for (int i = 0 ; i < n ; i++)
        {
            w[i] = sc.nextInt();
            val[i] = sc.nextInt();
            value+=val[i];
        }
        memo = new Long[n + 1][value + 9];
        int ans = solve(value);

        pw.print(ans);
        pw.close();
    }
    static class Point implements Comparable<Point>
    {
        int x ,y ;

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public int compareTo(Point o) {
            if (x == o.x) {
                return y - o.y;
            }
            return x - o.x;
        }

        @Override
        public String toString() {
            return "Point{" +
                    "x=" + x +
                    ", y=" + y +
                    '}';
        }
    }

    static class Circle implements Comparable<Circle>
    {
        int x , radius ,idx;
        public Circle(int x , int r , int idx)
        {
            this.x = x;
            this.radius = r;
            this.idx = idx;
        }

        public boolean isInside(Point p)
        {
            return (p.x - x)*(p.x - x) + (p.y)*(p.y) <= radius * radius;
        }

        @Override
        public String toString() {
            return "Circle{" +
                    "x=" + x +
                    ", radius=" + radius +
                    '}';
        }

        @Override
        public int compareTo(Circle o) {
            return x - o.x;
        }
    }

    private static long gcd(long a, long b) {
        if( b == 0)
            return a;
        return gcd(b  , a%b);
    }

    static long lcm(int a, int b)
    {
        return (a*b)/gcd(a, b);
    }


    private  static int dis(int xa , int ya , int xb , int yb)
    {
        return (xa-xb)*(xa - xb) + (ya- yb)*(ya-yb);
    }


    static class Pair implements Comparable<Pair> {
        int x,y;


        public Pair(int x, int y) {
            this.x = x;
            this.y = y;
        }

        public int compareTo(Pair o) {
            if (y  == o.y)
                return x - o.x;
            return y - o.y;

        }

        public double dis(Pair a){

            return (a.x - x)*(a.x - x) + (a.y-y)*(a.y-y);
        }

        public String toString() {
            return  x+" "+ y;
        }
        public boolean overlap(Pair a)
        {
            if((this.x >= a.x && this.x <= a.y) || (a.x >= this.x && a.x <= this.y)) return true;
            return false;

        }
    }

    static class Scanner {
        StringTokenizer st;
        BufferedReader br;

        public Scanner(FileReader r) {
            br = new BufferedReader(r);
        }

        public Scanner(InputStream s) {
            br = new BufferedReader(new InputStreamReader(s));
        }

        public String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return st.nextToken();
        }

        public boolean check() {
            if (!st.hasMoreTokens())
                return false;
            return true;
        }

        public int nextInt() {
            return Integer.parseInt(next());
        }

        public long nextLong() {
            return Long.parseLong(next());
        }

        public String nextLine() {
            try {
                return br.readLine();
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }

        public double nextDouble() {
            String x = next();
            StringBuilder sb = new StringBuilder("0");
            double res = 0, f = 1;
            boolean dec = false, neg = false;
            int start = 0;
            if (x.charAt(0) == '-') {
                neg = true;
                start++;
            }
            for (int i = start; i < x.length(); i++)
                if (x.charAt(i) == '.') {
                    res = Long.parseLong(sb.toString());
                    sb = new StringBuilder("0");
                    dec = true;
                } else {
                    sb.append(x.charAt(i));
                    if (dec)
                        f *= 10;
                }
            res += Long.parseLong(sb.toString()) / f;
            return res * (neg ? -1 : 1);
        }

        public boolean ready() {
            try {
                return br.ready();
            } catch (IOException e) {
                throw new RuntimeException(e);
            }
        }
    }
}