#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() { 
  ios::sync_with_stdio(false); cin.tie(0);
  int n, k;
  cin >> n >> k;
  vector<pair<int, int>> a(n);
  for (auto& p : a) cin >> p.first >> p.second;
  vector<vector<int>> dp(2, vector<int>(k + 1, -(1 << 30)));
  dp[0][0] = dp[1][0] = 0;
  sort(a.begin(), a.end());
  for (int i = 0; i < n; i++) {
    vector<vector<int>> nxt(2, vector<int>(k + 1, -(1 << 30)));
    auto p = a[i].first;
    auto d = a[i].second;
    for (int u = 0; u < 2; u++) {
      for (int j = 0; j <= k; j++) {
        int c = u == 0 ? p : 0;
        if (j + c <= k) nxt[u ^ 1][j + c] = max(nxt[u ^ 1][j + c], dp[u][j] + d);
        nxt[u][j] = max(nxt[u][j], dp[u][j]);
      }
    }
    dp.swap(nxt);
  }
  cout << *max_element(dp[1].begin(), dp[1].end()) << endl;
  return 0;
}