#include <fstream>

using namespace std;
const int N = 5000, K = 1e4 + 1;

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

int main()
{
    int n, k, g[N], p[N], sum[K], maxi = -1;
    in >> n >> k;
    for (int i = 0; i < n; i++)
    {
        in >> g[i] >> p[i];
    }
    for (int i = 1; i <= k; i++)
        sum[i] = -1;
    sum[0] = 0;
    for (int i = 0; i < n; i++)
    {
        for (int j = k - g[i]; j >= 0; j--)
        {
            if (sum[j] != -1 && sum[j] + p[i] > sum[j + g[i]])
                sum[j + g[i]] = sum[j] + p[i];
        }
    }
    for (int i = 1; i <= k; i++)
        maxi = max(maxi, sum[i]);
    out << maxi;
    return 0;
}