#include <iostream>
#include <fstream>

using namespace std;

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

const int nm=5002;
int profit[2*nm],g[nm],p[nm],n,k;

int main()
{
    int i,j,mx=-2;
    in>>n>>k;
    for(i=1;i<=n;i++)
    {
        in>>g[i]>>p[i];
    }
    for(j=1;j<=k;j++)
    {
        profit[j]=-1;
    }
    profit[0]=0;
    for(i=1;i<=n;i++)
    {
        for(j=k-g[i];j>=0;j--)
        {
            if(profit[j]+p[i]>profit[j+g[i]])
            {
               profit[j+g[i]]=profit[j]+p[i];
            }
        }
    }
    for(i=1;i<=k;i++)
    {
        if(profit[i]>mx)
        {
           mx=profit[i];
        }
    }
    out<<mx;
    return 0;
}