#include <bits/stdc++.h>

using namespace std;

ifstream f ("rucsac.in");
ofstream r("rucsac.out");

vector <int> greutati [3002];

int ans[2][3002];

int wmax,k;
int n, g,w,p;

struct obiect
{
    int pf;
    int kg;
} ob[36003];

bool mycmp (int a ,int b)
{
    return a>b;
}

int main()
{
    f>>n>>g;
    int p0=0;
    while (n--)
    {
        f>>w>>p;
        if (w==0)
        {
            p0+=p;
            continue;
        }
        greutati[w].push_back(p);
        wmax=max(wmax,w);

    }
    for (int i=1; i<=wmax; i++)
    {
        sort(greutati[i].begin(),greutati[i].end(),mycmp);
        int l=greutati[i].size();
        int stop=min(l ,g/i);
        for (int j=0; j<stop ; j++)
        {
            ob[++k].kg=i;
            ob[k].pf=greutati[i][j];
        }
    }
    int l1=0;
    int l2=1;
    for (int i=1; i<=k; i++)
    {
        for (int j=1; j<=g; j++)
        {
            if (ob[i].kg > j)
                ans[l2][j]=ans[l1][j];
            ans[l2][j]=max(ans[l1][j], ob[i].pf+ans[l1][j-ob[i].kg]);
        }
        swap(l1,l2);
    }
    if (k%2==0)
    r<<ans[0][g]+p0;
    else r<<ans[1][g]+p0;
}