#include <bits/stdc++.h>
#ifdef _DEBUG
#include "debug.hpp"
#else
#define debug(...)
#endif
#define REP(i, m, n) for(int i = (int)(m); i < (int)(n); ++i)
#define rep(i, n) REP(i, 0, n)
using namespace std;
using ll = long long; using ld = long double; using pll = pair<ll, ll>;
const int INF = 1<<30; const ll LINF = 1LL<<60; const ld PI = 3.1415926535897932;
template<class T, class U> inline bool chmax(T &a, const U &b) { if(a < b) { a = b; return true; } return false; }
template<class T, class U> inline bool chmin(T &a, const U &b) { if(a > b) { a = b; return true; } return false; }

int dp[5010][5010][2];

signed main() {
  cin.tie(0); ios::sync_with_stdio(false);
  int N, K;
  cin >> N >> K;
  vector<pll> p(N);
  rep(i, N) cin >> p[i].first >> p[i].second;
  sort(p.begin(), p.end(), greater<pll>());
  rep(i, 5010) rep(j, 5010) rep(k, 2) dp[i][j][k] = -INF;
  rep(j, 5010) dp[0][j][0] = 0;
  rep(i, N) rep(j, K+1) {
    rep(k, 2) {
      if(dp[i][j][k] == -INF) continue;
      chmax(dp[i+1][j][k], dp[i][j][k]);
    }
    if(dp[i][j][0] != -INF && j+p[i].first <= K) chmax(dp[i+1][j+p[i].first][1], dp[i][j][0]+p[i].second);
    if(dp[i][j][0] != -INF) chmax(dp[i+1][j][0], dp[i][j][1]+p[i].second);
  }
  int ans = max(dp[N][K][1], dp[N][K][0]);
  cout << ans << '\n';
  return 0;
}