#include <iostream>
#include<cmath>
#include<fstream>

using namespace std;

ifstream f ("energii.in");

ofstream g ("energii.out");

struct ele

{

    int gr,val;

}v[10001];

int n,s,i,j,maxim,valoare,minim=9999999;

int c[1002][1002];//a[1002][10002];

int main()

{

    f>>n>>valoare;



    for(i=1;i<=n;i++)

        f>>v[i].val>>v[i].gr,maxim+=v[i].gr;
 for(i=1;i<=n;i++)
     for(j=1;j<=maxim+maxim/2;j++)
  {

     if(j>=v[i].gr && c[i-1][j-v[i].gr]+v[i].val>c[i-1][j])
     {

        c[i][j]=c[i-1][j-v[i].gr]+v[i].val;
         if(j<=minim && c[i][j]>=valoare)
               minim=j;
     }
     else
        c[i][j]=c[i-1][j];
  }
  g<<minim;
}