#include <iostream>
#include <fstream>
#define gmax 1002
#define wmax 5002
using namespace std;

int dp[gmax][wmax],w[gmax],c[gmax],G,W;

int main()
{
    ifstream fin ("energii.in");
    ofstream fout("energii.out");
    fin>>G>>W;
    for(int i=1; i<=G; i++)
        fin>>w[i]>>c[i];
    for(int i=1; i<=G; i++)
        dp[i][0]=1;
    for(int i=1; i<=G; i++)
    {
        for(int j=1; j<=W; j++)
        {
            if(dp[i][j-w[i]])
            {
                dp[i][j]=dp[i][j-w[i]]+w[i];
                //if(!(j-w[i]))
                    //dp[i][j]--;
            }
            else if(dp[i-1][j-w[i]])
            {
                dp[i][j]=dp[i-1][j-w[i]];
               //if(!(j-w[i]))
                    //dp[i][j]--;
            }
        }
    }
    fout<<dp[G][W];
    return 0;
}