#include<bits/stdc++.h>

using namespace std;
ifstream fin("rucsac.in");
ofstream fout("rucsac.out");
const int NMAX = 10000;
#define ll long long

ll dp[NMAX+5];


int main()
{

    int n;
    fin>>n;
    ll g, a, b;
    fin>>g;
    for(int i = 1; i <= g; i++)
       dp[i] = -1;
    ll j = 0;
    for(int i = 1; i <=n;i++)
    {
        fin>>a>>b;
        for(ll k = j; k >= 0; k--)
        {
           if(dp[k] == -1)
             continue;
           if(k + a  <= g)
           {
              dp[k + a] = max(dp[k + a], dp[k] + b);
              j = max(j, k + a);
           }
        }
    }
    fout<<dp[g]<<"\n";

    return 0;
}