#include <iostream>
#include <fstream>

using namespace std;
ifstream fin ("rucsac.in");
ofstream fout ("rucsac.out");

int m[5001][10001];
int Gmax,g,v,auxv;
short n;
int main()
{
    fin>>n>>Gmax;
    for (int i=1;i<=n;i++)
    {
        fin>>g>>v;
        g++;
        v++;
        for (int j=g;j<=Gmax;j++)
        {
            auxv=v+m[i-1][j-g];
            if (auxv>m[i-1][j])
                m[i][j]=auxv;
            else m[i][j]=m[i-1][j];
        }
        for (int j=1;j<g;j++)
            m[i][j]=m[i-1][j];
    }
    fout<<m[n][Gmax]-1;
    return 0;
}