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: Accepted)

import java.util.*;
import java.io.*;
//267630EY
public class Main
{
  static PrintWriter out=new PrintWriter(System.out);

  public static void main(String[] args) throws IOException
  {
    Scanner sc=new Scanner(System.in);
    int n=sc.nextInt();
    int w=sc.nextInt();
    int[] val=new int[n];
    int[] weights=new int[n];
    int sum=0;
    for(int i=0;i<n;i++)
    {
      
      weights[i]=sc.nextInt();
      val[i]=sc.nextInt();
      sum+=val[i];
    }
    
   
    long[] dp=new long[sum+1];
    long INF=(long)10e15;
    Arrays.fill(dp,INF);
    
    dp[0]=0;
    for(int i=0;i<n;i++)
    {
      for(int j=sum;j>=val[i];j--)
      {
        dp[j]=Math.min(dp[j],dp[j-val[i]]+(long)weights[i]);
      }
    }
    long ans=0;
    for(int i=sum;i>=0;i--)
    {
      if(dp[i]<=w)
      {
        ans=i;
        break;
      }
    }
    out.println(ans);
    out.flush();
   
      

        
   
      
      
                
    
  }
  
  static class Scanner
  {
    BufferedReader br;
    StringTokenizer tk=new StringTokenizer("");
    public Scanner(InputStream is) 
    {
      br=new BufferedReader(new InputStreamReader(is));
    }
    
    public boolean hasNext()
    {
      

      boolean result=false;
      
      try 
      {
        result = br.ready();
      } 
      catch (IOException e)
      {
        System.err.println(e);
      }
      return result;
    }
    
    public int nextInt() throws IOException
    {
      if(tk.hasMoreTokens())
        return Integer.parseInt(tk.nextToken());
      tk=new StringTokenizer(br.readLine());
      return nextInt();
    }
    public long nextLong() throws IOException
    {
      if(tk.hasMoreTokens())
        return Long.parseLong(tk.nextToken());
      tk=new StringTokenizer(br.readLine());
      return nextLong();
    }
    public String next() throws IOException
    {
      if(tk.hasMoreTokens())
        return (tk.nextToken());
      tk=new StringTokenizer(br.readLine());
      return next();
    }
    public String nextLine() throws IOException
    {
      tk=new StringTokenizer("");
      return br.readLine();
    }
    public double nextDouble() throws IOException
    {
      if(tk.hasMoreTokens())
        return Double.parseDouble(tk.nextToken());
      tk=new StringTokenizer(br.readLine());
      return nextDouble();
    }
    public char nextChar() throws IOException
    {
      if(tk.hasMoreTokens())
        return (tk.nextToken().charAt(0));
      tk=new StringTokenizer(br.readLine());
      return nextChar();
    }
    public int[] nextIntArray(int n) throws IOException
    {
      int a[]=new int[n];
      for(int i=0;i<n;i++)
        a[i]=nextInt();
      return a;
    }
    public long[] nextLongArray(int n) throws IOException
    {
      long a[]=new long[n];
      for(int i=0;i<n;i++)
        a[i]=nextLong();
      return a;
    }
    public int[] nextIntArrayOneBased(int n) throws IOException
    {
      int a[]=new int[n+1];
      for(int i=1;i<=n;i++)
        a[i]=nextInt();
      return a;
    }
    public long[] nextLongArrayOneBased(int n) throws IOException
    {
      long a[]=new long[n+1];
      for(int i=1;i<=n;i++)
        a[i]=nextLong();
      return a;
    }
  }
}