#include <iostream>
#include <fstream>
#include <cstdio>
#define NMAX 5001
#define GMAX 10001


using namespace std;

int Valoare[NMAX] , Greutati[NMAX] , Vect[GMAX];
int Nr_obiecte , Gr_maxima;
ifstream input("rucsac.in");
ofstream output("rucsac.out");

int dinamica()
{
    int solutie = -1;
    for (int i = 0;i<GMAX;i++)
        Vect[i] = 0;

    for (int i = 0;i<Nr_obiecte;i++)
        for (int j = Gr_maxima - Greutati[i];j>=0;j--)
            if (Vect[j + Greutati[i]] < Vect[j] + Valoare[i])
            {
                Vect[j + Greutati[i]] = Vect[j] + Valoare[i];
                if (solutie < Vect[j + Greutati[i]])
                    solutie = Vect[j + Greutati[i]];
            }
    return solutie;
}

int main()
{
    input >> Nr_obiecte >> Gr_maxima;
    for (int i = 0; i<Nr_obiecte;i++)
    {
        input >> Greutati[i] >> Valoare[i];
    }
    output << dinamica();
    input.close();
    output.close();
    return 0;
}