#include <iostream>
#include <fstream>
#include <utility>
#include <vector>
#include <map>
using namespace std;
vector<pair<int, int> > Ob;
int nrO, G, a, b, pMax;

void RucsacNxG ();
void RucsacHash ();
void Read ();
int main()
{
    Read();
    //RucsacNxG();
    RucsacHash();
}
void RucsacHash()
{
    map<int, int> M, M2;
    M2.insert(make_pair(0, 0));
    int Solution = -((1<<31)-1);
    for(int i = 1; i <= nrO; ++i)
    {
        for(map<int, int>::iterator it = M2.begin(); it != M2.end(); ++it)
        {
            int newG = it->first + Ob[i].first;
            if(newG <= G) {                                                     // Adauga un nou obiect
                int newProfit = it->second + Ob[i].second;
                map<int, int>::iterator newEl = M2.find(newG);
                if(newEl == M2.end())
                    M.insert(make_pair(newG, newProfit));
                else
                    M.insert(make_pair(newG, max(newProfit, newEl->second)));
            }
                                                                                // Pastreaza valoarile pentru greutatile deja calculate
            map<int, int>::iterator originalEl = M.find(it->first);
            if(originalEl != M.end())
                M[originalEl->first] = max(it->second, originalEl->second);
            else
                M[it->first] = max(it->second, originalEl->second);
        }
        M2.erase(M2.begin(), M2.end());
        M2.insert(M.begin(), M.end());

        M.erase(M.begin(), M.end());
    }
    for(map<int, int>::iterator it = M2.begin(); it != M2.end() && it->first <= G; ++it)
        Solution = max(Solution, it->second);
    cout<<Solution<<'\n';
}
void RucsacNxG()
{
    vector<int>D(G+1);
    for(int o=1; o<=nrO; ++o)
        for( int g=G; g>=0; --g)
            if(Ob[o].first <= g)
                D[g] = max(D[g], (D[g - Ob[o].first] + Ob[o].second) );

    for(int i=0; i<=G; ++i)
        pMax = max(pMax, D[i]);
    cout<<pMax<<'\n';
}
void Read ()
{
    freopen("rucsac.in", "rt", stdin);
    freopen("rucsac.out", "wt", stdout);
    scanf("%d%d", &nrO, &G);
    Ob.push_back(make_pair(0, 0));
    for(int i=1; i<=nrO; ++i){
        scanf("%d%d", &a, &b);
        Ob.push_back(make_pair(a, b));
    }
}