#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i = 0; i < (n);i++)
#define sz(x) int(x.size())
typedef long long ll;
typedef pair<int,int> P;
constexpr ll INF = 1e18;
int main(){
  int n, K;
  cin >> n >> K;
  vector<P> A(n);
  rep(i,n) {
    int p, d;
    cin >> p >> d;
    A[i] = make_pair(p, d);
  }
  sort(A.begin(), A.end(), greater<P>());
  vector<vector<ll>> dp(K+1, vector<ll>(2,-INF));
  dp[0][0] = 0;
  for (int i = 0; i < n; i++) {
    auto next = dp;
    for (int j = 0; j <= K; j++) {
      if (j + A[i].first <= K) next[j + A[i].first][1] = max(next[j + A[i].first][1], dp[j][0] + A[i].second);
      next[j][0] = max(next[j][0], dp[j][1] + A[i].second);
      next[j][0] = max(next[j][0], dp[j][0]);
      next[j][1] = max(next[j][1], dp[j][1]);
    }
    dp = next;
  }
  ll res = 0;
  for (int i = 0; i <= K; i++) res = max(res, max(dp[i][0], dp[i][1]));
  cout << res << endl;
  return 0;
}