#include <fstream>
#define MaxN 5001
#define MaxG 10001
using namespace std;

ifstream is("rucsac.in");
ofstream os("rucsac.out");

void Read();
void Write();
void Knapsack();

int c[MaxG];
int w[MaxN], p[MaxN];
int n, g, sol = -1;

int main()
{
    Read();
    Knapsack();
    Write();

    is.close();
    os.close();
    return 0;
}

void Read()
{
    is >> n >> g;
    for ( int i = 1; i <= n; ++i )
        is >> w[i] >> p[i];
}

void Write()
{
    os << sol;
}

void Knapsack()
{
    for ( int i = 1; i <= n; ++i )
        for ( int j = g - w[i]; j >= 0; --j )
            if ( c[j + w[i]] < c[j] + p[i] )
            {
                c[j + w[i]] = c[j] + p[i];
                sol = max(sol, c[j + w[i]]);
            }
}