Language: C++

//#pragma GCC optimize("O3")
//#pragma GCC target("avx")

#include <algorithm>
#include <cmath>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

// Types
using ll = long long int;
using str = string;
template <class F,
          typename enable_if<is_function<F>::value, nullptr_t>::type = nullptr>
using fun = function<F>;

namespace io {
// Input
using IS = istream;
IS &in(IS &);
IS &in(IS &i) { return i; }
template <class T, class... Ts> IS &in(IS &i, T &a, Ts &... as) {
  return in(i >> a, as...);
}
template <class V> IS &operator>>(IS &i, vector<V> &a) {
  for_each(a.begin(), a.end(), [&i](auto &e) { i >> e; });
  return i;
}
template <class F, class S> IS &operator>>(IS &i, pair<F, S> &p) {
  return in(i, p.first, p.second);
}
template <class... Ts, size_t... I>
IS &tuple_in(IS &i, tuple<Ts...> &t, index_sequence<I...>) {
  return in(i, get<I>(t)...);
}
template <class... Ts> IS &operator>>(IS &i, tuple<Ts...> &t) {
  return tuple_in(i, t, make_index_sequence<sizeof...(Ts)>());
}
// Output
using OS = ostream;
OS &out(OS &o) { return o << endl; }
template <class T> OS &out(OS &o, T const &a) { return o << a << endl; }
template <class T, class... Ts> OS &out(OS &o, T const &a, Ts const &... as) {
  return out(o << a << " ", as...);
}
template <class F, class S> OS &operator<<(OS &o, pair<F, S> const &p) {
  return o << p.first << ":" << p.second;
}
template <class... Ts> OS &args_out(OS &o, Ts const &... ts);
OS &args_out(OS &o) { return o; }
template <class T> OS &args_out(OS &o, T const &t) { return o << t; }
template <class T0, class T1, class... Ts>
OS &args_out(OS &o, T0 const &t0, T1 const &t1, Ts const &... ts) {
  return args_out(o << t0 << ",", t1, ts...);
}
template <class... Ts, size_t... I>
OS &tuple_out(OS &o, tuple<Ts...> const &t, index_sequence<I...>) {
  return args_out(o, get<I>(t)...);
}
template <class... Ts> OS &operator<<(OS &o, tuple<Ts...> const &t) {
  return tuple_out(o << "(", t, make_index_sequence<sizeof...(Ts)>()) << ")";
}
template <
    class C,
    class T = typename iterator_traits<typename C::iterator>::value_type,
    typename enable_if<!is_same<C, str>::value, nullptr_t>::type = nullptr>
OS &operator<<(OS &o, C const &a) {
  return a.empty() ? (o << "[]") : ([&o, &a]() -> OS & {
    o << "[" << *a.begin();
    for_each(next(a.begin()), a.end(), [&o](auto const &e) { o << "," << e; });
    return o << "]";
  }());
}
} // namespace io
auto input = [](auto &... a) { io::in(cin, a...); };
auto print = [](auto const &... a) { io::out(cout, a...); };
#ifdef JUMPAKU_DEBUG
auto dump = [](auto const &... a) { io::out(cerr, a...); };
#else
auto dump = [](auto const &...) {};
#endif

// Hash
namespace hashcode {
template <class... Ts> uint64_t hash_args(uint64_t h, Ts const &... ts);
uint64_t hash_args(uint64_t h) { return h; }
template <class T, class... Ts>
uint64_t hash_args(uint64_t h, T const &t, Ts const &... ts) {
  constexpr hash<T> hasher;
  return hash_args(((h << 19) - h) ^ hasher(t), ts...);
}
template <class... Ts, size_t... I>
uint64_t hash_tuple(tuple<Ts...> const &t, index_sequence<I...>) {
  return hash_args(59, get<I>(t)...);
}
} // namespace hashcode
namespace std {
template <class... Ts> struct hash<tuple<Ts...>> {
  size_t operator()(tuple<Ts...> const &t) const {
    uint64_t h = hashcode::hash_tuple(t, index_sequence_for<Ts...>());
    return h ^ (h >> 32);
  }
};
} // namespace std

// Range
namespace ranges {
template <class T> struct iterator_base {
  using difference_type = ll;
  using value_type = T;
  using pointer = T *;
  using reference = T &;
  using iterator_category = random_access_iterator_tag;
  ll i;
  iterator_base(ll const &i = 0) : i(i) {}
  bool operator==(iterator_base const &itr) const { return i == itr.i; }
  bool operator!=(iterator_base const &itr) const { return i != itr.i; }
  ll operator-(iterator_base const &itr) const { return i - itr.i; }
};
template <class T> struct seq_base {
  ll const b;
  ll const e;
  seq_base(ll b, ll e) : b(b), e(e) {}
  ll size() const { return e - b; }
  bool empty() const { return size() == 0; }
};
template <class T> struct seq : seq_base<T> {
  struct iterator : iterator_base<T> {
    seq *s;
    iterator(seq *s, ll const &i) : iterator_base<T>(i), s(s) {}
    iterator operator++(int) { return iterator(s, this->i++); }
    iterator operator--(int) { return iterator(s, this->i--); }
    iterator operator+(ll const &n) { return iterator(s, this->i + n); }
    iterator operator-(ll const &n) { return iterator(s, this->i - n); }
    iterator &operator+=(ll const &n) {
      this->i += n;
      return *this;
    }
    iterator &operator-=(ll const &n) { return *this += (-n); }
    iterator &operator++() { return *this += 1; }
    iterator &operator--() { return *this -= 1; }
    T operator*() const { return (*s)[this->i]; }
  };
  function<T(ll)> const f;
  seq(ll n, function<T(ll)> const &f) : seq(0, n, f) {}
  seq(ll b, ll e, function<T(ll)> const &f) : seq_base<T>(b, e), f(f) {}
  iterator begin() { return iterator(this, this->b); }
  iterator end() { return iterator(this, this->e); }
  ll operator[](ll i) const { return f(i); }
};
struct range : seq_base<ll> {
  struct iterator : iterator_base<ll> {
    iterator(ll const &i) : iterator_base<ll>(i) {}
    iterator operator++(int) { return iterator(i++); }
    iterator operator--(int) { return iterator(i--); }
    iterator operator+(ll const &n) const { return iterator(i + n); }
    iterator operator-(ll const &n) const { return iterator(i - n); }
    iterator &operator+=(ll const &n) {
      i += n;
      return *this;
    }
    iterator &operator-=(ll const &n) { return *this += (-n); }
    iterator &operator++() { return *this += 1; }
    iterator &operator--() { return *this -= 1; }
    ll operator*() const { return i; }
  };
  range(ll n) : range(0LL, n) {}
  range(ll b, ll e) : seq_base<ll>(b, e) {}
  iterator begin() const { return iterator(b); }
  iterator end() const { return iterator(e); }
  ll operator[](ll i) const { return i + b; }
};
} // namespace ranges
using range = ranges::range;
range::iterator range_end(ll i) { return ranges::range::iterator(i); }
range::iterator range_begin(ll i) { return range_end(i); }
template <class F> auto seq(ll b, ll e, F const &f) {
  using T = decltype(f(declval<ll>()));
  return ranges::seq<T>(b, e, f);
}
template <class F> auto seq(ll n, F const &f) { return seq(0, n, f); }
template <class T = ll> vector<T> vec(size_t n, T &&init = T()) {
  return vector<T>(n, init);
}

ll gcd(ll p, ll q) { return (q == 0) ? p : gcd(q, p % q); }
ll lcm(ll p, ll q) { return p / gcd(q, p) * q; }

// MOD
ll pow(ll a, ll n, ll m) {
  if (n == 0)
    return 1;
  if (n & 1)
    return ((a % m) * pow(a, n - 1, m)) % m;
  auto b = pow(a, n / 2, m);
  return (b * b) % m;
}
ll inv(ll a, ll p) { return pow(a, p - 2, p); }

template <ll N, ll M> struct Factrial {
  Factrial() {
    fact[0] = 1;
    for (int i = 1; i <= N; ++i)
      fact[i] = (fact[i - 1] * i) % M;
    finv[N] = inv(fact[N], M);
    for (int i = N; i > 0; --i)
      finv[i - 1] = (finv[i] * i) % M;
  }
  array<ll, N + 1> fact;
  array<ll, N + 1> finv;
  ll comb(ll n, ll m) const {
    if (m < 0 || n < m)
      return 0LL;
    return (fact[n] * ((finv[m] * finv[n - m]) % M)) % M;
  }
};

constexpr ll MOD = 1e9 + 7;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
template <class V, class H = std::hash<V>>
using u_set = __gnu_pbds::gp_hash_table<V, __gnu_pbds::null_type, H>;
template <class K, class V, class H = std::hash<K>>
using u_map = __gnu_pbds::gp_hash_table<K, V, H>;
using Key = tuple<ll, ll>;
ll f(Key const &key, vector<tuple<ll, ll>> const &AB, u_map<Key, ll> &dp) {
  ll t = get<0>(key);
  ll i = get<1>(key);
  if (t <= 0)
    return 0;
  auto Ai = get<0>(AB[i]);
  auto Bi = get<1>(AB[i]);
  if (i == 0)
    return Bi;
  // if (dp.contains(key))
  if (dp.find(key) != dp.end())
    return dp[key];
  return dp[key] =
             max(f(Key{t - Ai, i - 1}, AB, dp) + Bi, f(Key{t, i - 1}, AB, dp));
}
int main() {
  ll N, T;
  input(N, T);
  auto AB = vec<tuple<ll, ll>>(N);
  for (auto &&i : range(N)) {
    ll a, b;
    input(a, b);
    AB[i] = {a, b};
  }

  sort(AB.begin(), AB.end(),
       [](auto const &x0, auto const &x1) { return get<0>(x0) > get<0>(x1); });
  // dump(N, T, AB);
  auto dp = u_map<Key, ll>();
  dp.resize(2e6);
  ll ans = f(Key{T, N - 1}, AB, dp);
  print(ans);
}


Compiler output:
In file included from /usr/include/c++/14/ext/pb_ds/tag_and_trait.hpp:46,
                 from /usr/include/c++/14/ext/pb_ds/assoc_container.hpp:46,
                 from a.cc:236:
/usr/include/c++/14/ext/pb_ds/detail/resize_policy/hash_standard_resize_policy_imp.hpp: In instantiation of 'void __gnu_pbds::hash_standard_resize_policy<Size_Policy, Trigger_Policy, External_Size_Access, Size_Type>::resize(size_type) [with Size_Policy = __gnu_pbds::hash_exponential_size_policy<>; Trigger_Policy = __gnu_pbds::hash_load_check_resize_trigger<>; bool External_Size_Access = false; Size_Type = long unsigned int; size_type = long unsigned int]':
a.cc:272:12:   required from here
  272 |   dp.resize(2e6);
      |   ~~~~~~~~~^~~~~
/usr/include/c++/14/ext/pb_ds/detail/resize_policy/hash_standard_resize_policy_imp.hpp:189:3: error: static assertion failed: access
  189 |   PB_DS_STATIC_ASSERT(access, external_size_access);
      |   ^~~~~~~~~~~~~~~~~~~
/usr/include/c++/14/ext/pb_ds/detail/resize_policy/hash_standard_resize_policy_imp.hpp:189:3: note: '__gnu_pbds::hash_standard_resize_policy<__gnu_pbds::hash_exponential_size_policy<>, __gnu_pbds::hash_load_check_resize_trigger<>, false, long unsigned int>::external_size_access' evaluates to false