#include <bits/stdc++.h>
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (n); i++)
#define repr(i, n) for (int i = (n) - 1; i >= 0; i--)
#define range(a) a.begin(), a.end()

void chmax(int &x, int y) {
  x = max(x, y);
}

int main() {
  int N, K; cin >> N >> K;
  vector<int> P(N), D(N); rep(i, N) cin >> P[i] >> D[i];
  vector<int> ord(N); rep(i, N) ord[i] = i;
  sort(range(ord), [&](int i, int j) { return P[i] < P[j]; });
  const int inf = 1e9;
  vector<int> dp0(K + 1, -inf);
  vector<int> dp1(K + 1, -inf);
  dp0[0] = 0;
  for (int i : ord) {
    vector<int> ep0(K + 1, -inf);
    vector<int> ep1(K + 1, -inf);
    for (int j = 0; j <= K; j++) {
      chmax(ep0[j], dp0[j]);
      chmax(ep1[j], dp1[j]);
      chmax(ep1[j], dp0[j] + D[i]);
      if (j + P[i] <= K) {
        chmax(ep0[j + P[i]], dp0[j] + D[i]);
        chmax(ep0[j + P[i]], dp1[j] + D[i]);
      }
    }
    dp0 = ep0;
    dp1 = ep1;
  }
  int ans = -inf;
  for (int i = 0; i <= K; i++) {
    chmax(ans, dp0[i]);
  }
  cout << ans << endl;
}