#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdint>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <list>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <stack>
#include <unordered_map>
#include <unordered_set>

/*
1 2 4
1 3 10
1 4 4
1 5 10
1 6 8
1 7 20
1 8 17
2 3 2
2 4 16
2 5 26
2 6 20
2 7 40
2 8 25
3 4 26
3 5 36
3 6 26
3 7 50
3 8 25
4 5 2
4 6 4
4 7 8
4 8 17
5 6 2
5 7 2
5 8 13
6 7 4
6 8 5
7 8 13


*/
template <typename T1, typename T2>
std::ostream &operator<<(std::ostream &os, const std::pair<T1, T2> &p) {
  os << p.first << " " << p.second;
  return os;
}

template <typename T1, typename T2>
std::istream &operator>>(std::istream &is, std::pair<T1, T2> &p) {
  is >> p.first >> p.second;
  return is;
}

template <typename T>
std::ostream &operator<<(std::ostream &os, const std::vector<T> &v) {
  for (int i = 0; i < (int)v.size(); i++) {
    os << v[i] << (i + 1 != (int)v.size() ? " " : "");
  }
  return os;
}

template <typename T>
std::istream &operator>>(std::istream &is, std::vector<T> &v) {
  for (T &in : v) is >> in;
  return is;
}
template <int mod>
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt &operator+=(const ModInt &p) {
    if ((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if ((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (int)(1LL * x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }
  ModInt &operator^=(long long p) {  // quick_pow here:3
    ModInt res = 1;
    for (; p; p >>= 1) {
      if (p & 1) res *= *this;
      *this *= *this;
    }
    return *this = res;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  ModInt operator^(long long p) const { return ModInt(*this) ^= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }
  explicit operator int() const { return x; }  // added by QCFium
  ModInt operator=(const int p) {
    x = p;
    return ModInt(*this);
  }  // added by QCFium
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      a -= t * b;
      std::swap(a, b);
      u -= t * v;
      std::swap(u, v);
    }
    return ModInt(u);
  }
  friend std::ostream &operator<<(std::ostream &os, const ModInt<mod> &p) {
    return os << p.x;
  }
  friend std::istream &operator>>(std::istream &is, ModInt<mod> &a) {
    long long x;
    is >> x;
    a = ModInt<mod>(x);
    return (is);
  }
};
using mint = ModInt<1000000007>;
// using mint = ModInt<998244353>;
const int MOD = 998244353;
template <typename T>
std::pair<std::vector<T>, std::vector<T>> get_prime_factor_with_kinds(T n) {
  std::vector<T> prime_factors;
  std::vector<T> cnt;  // number of i_th factor
  for (T i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      prime_factors.push_back(i);
      cnt.push_back(0);
      while (n % i == 0) n /= i, cnt[(int)prime_factors.size() - 1]++;
    }
  }
  if (n > 1) prime_factors.push_back(n), cnt.push_back(1);
  assert(prime_factors.size() == cnt.size());
  return {prime_factors, cnt};
}

/*
Range Add Range Sum

struct S {
  long long value;
  int size;
};
using F = long long;

S op(S a, S b) { return {a.value + b.value, a.size + b.size}; }
S e() { return {0, 0}; }
S mapping(F f, S x) { return {x.value + f * x.size, x.size}; }
F composition(F f, F g) { return f + g; }
F id() { return 0; }

Ranged affine range sum
struct S {
  mint sum;
  int len;
};
struct F {
  mint a;
  mint b;
};

S op(S l, S r) { return {l.sum + r.sum, l.len + r.len}; }
S e() { return {0, 0}; }
S mapping(F lazy, S node) {
  return {node.sum * lazy.a + node.len * lazy.b, node.len};
}
F composition(F f, F g) {  // f is son, g is parent
  return {f.a * g.a, g.b * f.a + f.b};
}

F id() { return {1, 0}; }

*/

// #pragma once

#include <bit>
#include <cassert>
#include <functional>
#include <vector>

namespace atcoder {

namespace internal {

#if __cplusplus >= 202002L

using std::bit_ceil;

#else

// @return same with std::bit::bit_ceil
unsigned int bit_ceil(unsigned int n) {
  unsigned int x = 1;
  while (x < (unsigned int)(n)) x *= 2;
  return x;
}

#endif

// @param n `1 <= n`
// @return same with std::bit::countr_zero
int countr_zero(unsigned int n) {
#ifdef _MSC_VER
  unsigned long index;
  _BitScanForward(&index, n);
  return index;
#else
  return __builtin_ctz(n);
#endif
}

// @param n `1 <= n`
// @return same with std::bit::countr_zero
constexpr int countr_zero_constexpr(unsigned int n) {
  int x = 0;
  while (!(n & (1 << x))) x++;
  return x;
}

}  // namespace internal

}  // namespace atcoder

namespace atcoder {

#if __cplusplus >= 201703L

template <class S, auto op, auto e, class F, auto mapping, auto composition,
          auto id>
struct lazy_segtree {
  static_assert(std::is_convertible_v<decltype(op), std::function<S(S, S)>>,
                "op must work as S(S, S)");
  static_assert(std::is_convertible_v<decltype(e), std::function<S()>>,
                "e must work as S()");
  static_assert(
      std::is_convertible_v<decltype(mapping), std::function<S(F, S)>>,
      "mapping must work as F(F, S)");
  static_assert(
      std::is_convertible_v<decltype(composition), std::function<F(F, F)>>,
      "compostiion must work as F(F, F)");
  static_assert(std::is_convertible_v<decltype(id), std::function<F()>>,
                "id must work as F()");

#else

template <class S, S (*op)(S, S), S (*e)(), class F, S (*mapping)(F, S),
          F (*composition)(F, F), F (*id)()>
struct lazy_segtree {

#endif

 public:
  lazy_segtree() : lazy_segtree(0) {}
  explicit lazy_segtree(int n) : lazy_segtree(std::vector<S>(n, e())) {}
  explicit lazy_segtree(const std::vector<S> &v) : _n(int(v.size())) {
    size = (int)internal::bit_ceil((unsigned int)(_n));
    log = internal::countr_zero((unsigned int)size);
    d = std::vector<S>(2 * size, e());
    lz = std::vector<F>(size, id());
    for (int i = 0; i < _n; i++) d[size + i] = v[i];
    for (int i = size - 1; i >= 1; i--) {
      update(i);
    }
  }

  void set(int p, S x) {
    assert(0 <= p && p < _n);
    p += size;
    for (int i = log; i >= 1; i--) push(p >> i);
    d[p] = x;
    for (int i = 1; i <= log; i++) update(p >> i);
  }

  S get(int p) {
    assert(0 <= p && p < _n);
    p += size;
    for (int i = log; i >= 1; i--) push(p >> i);
    return d[p];
  }

  S prod(int l, int r) {
    assert(0 <= l && l <= r && r <= _n);
    if (l == r) return e();

    l += size;
    r += size;

    for (int i = log; i >= 1; i--) {
      if (((l >> i) << i) != l) push(l >> i);
      if (((r >> i) << i) != r) push((r - 1) >> i);
    }

    S sml = e(), smr = e();
    while (l < r) {
      if (l & 1) sml = op(sml, d[l++]);
      if (r & 1) smr = op(d[--r], smr);
      l >>= 1;
      r >>= 1;
    }

    return op(sml, smr);
  }

  S all_prod() { return d[1]; }

  void apply(int p, F f) {
    assert(0 <= p && p < _n);
    p += size;
    for (int i = log; i >= 1; i--) push(p >> i);
    d[p] = mapping(f, d[p]);
    for (int i = 1; i <= log; i++) update(p >> i);
  }
  void apply(int l, int r, F f) {
    assert(0 <= l && l <= r && r <= _n);
    if (l == r) return;

    l += size;
    r += size;

    for (int i = log; i >= 1; i--) {
      if (((l >> i) << i) != l) push(l >> i);
      if (((r >> i) << i) != r) push((r - 1) >> i);
    }

    {
      int l2 = l, r2 = r;
      while (l < r) {
        if (l & 1) all_apply(l++, f);
        if (r & 1) all_apply(--r, f);
        l >>= 1;
        r >>= 1;
      }
      l = l2;
      r = r2;
    }

    for (int i = 1; i <= log; i++) {
      if (((l >> i) << i) != l) update(l >> i);
      if (((r >> i) << i) != r) update((r - 1) >> i);
    }
  }

  template <bool (*g)(S)>
  int max_right(int l) {
    return max_right(l, [](S x) { return g(x); });
  }
  template <class G>
  int max_right(int l, G g) {
    assert(0 <= l && l <= _n);
    assert(g(e()));
    if (l == _n) return _n;
    l += size;
    for (int i = log; i >= 1; i--) push(l >> i);
    S sm = e();
    do {
      while (l % 2 == 0) l >>= 1;
      if (!g(op(sm, d[l]))) {
        while (l < size) {
          push(l);
          l = (2 * l);
          if (g(op(sm, d[l]))) {
            sm = op(sm, d[l]);
            l++;
          }
        }
        return l - size;
      }
      sm = op(sm, d[l]);
      l++;
    } while ((l & -l) != l);
    return _n;
  }

  template <bool (*g)(S)>
  int min_left(int r) {
    return min_left(r, [](S x) { return g(x); });
  }
  template <class G>
  int min_left(int r, G g) {
    assert(0 <= r && r <= _n);
    assert(g(e()));
    if (r == 0) return 0;
    r += size;
    for (int i = log; i >= 1; i--) push((r - 1) >> i);
    S sm = e();
    do {
      r--;
      while (r > 1 && (r % 2)) r >>= 1;
      if (!g(op(d[r], sm))) {
        while (r < size) {
          push(r);
          r = (2 * r + 1);
          if (g(op(d[r], sm))) {
            sm = op(d[r], sm);
            r--;
          }
        }
        return r + 1 - size;
      }
      sm = op(d[r], sm);
    } while ((r & -r) != r);
    return 0;
  }

 private:
  int _n, size, log;
  std::vector<S> d;
  std::vector<F> lz;

  void update(int k) { d[k] = op(d[2 * k], d[2 * k + 1]); }
  void all_apply(int k, F f) {
    d[k] = mapping(f, d[k]);
    if (k < size) lz[k] = composition(f, lz[k]);
  }
  void push(int k) {
    all_apply(2 * k, lz[k]);
    all_apply(2 * k + 1, lz[k]);
    lz[k] = id();
  }
};

}  // namespace atcoder

using S = long long;
using F = long long;

const S INF = 8e18;

S op(S a, S b) { return std::max(a, b); }
S e() { return -INF; }
S mapping(F f, S x) { return f + x; }
F composition(F f, F g) { return f + g; }
F id() { return 0; }

double get_e(double x1, double y1, double x2, double y2) {
  return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}

// knight move

template <typename T>
struct DoublingLowestCommonAncestor {
  std::vector<std::vector<std::pair<int, T>>> g;

  std::vector<int> dep;
  std::vector<T> sum;
  std::vector<std::vector<int>> table;
  const int LOG;

  explicit DoublingLowestCommonAncestor(int n)
      : g(n), LOG(32 - __builtin_clz(n)) {}

  void add_edge(int u, int v, T w = 1) {
    g[u].emplace_back(v, w);
    g[v].emplace_back(u, w);
  }

  void build(int root = 0) {
    dep.assign(g.size(), 0);
    sum.assign(g.size(), 0);
    table.assign(LOG, std::vector<int>(g.size(), -1));
    dfs(root, -1, 0);
    for (int k = 0; k + 1 < LOG; k++) {
      for (int i = 0; i < (int)table[k].size(); i++) {
        if (table[k][i] == -1)
          table[k + 1][i] = -1;
        else
          table[k + 1][i] = table[k][table[k][i]];
      }
    }
  }

  int lca(int u, int v) {
    if (dep[u] > dep[v]) std::swap(u, v);
    v = climb(v, dep[v] - dep[u]);
    if (u == v) return u;
    for (int i = LOG - 1; i >= 0; i--) {
      if (table[i][u] != table[i][v]) {
        u = table[i][u];
        v = table[i][v];
      }
    }
    return table[0][u];
  }

  int climb(int u, int k) {
    if (dep[u] < k) return -1;
    for (int i = LOG - 1; i >= 0; i--) {
      if ((k >> i) & 1) u = table[i][u];
    }
    return u;
  }

  T dist(int u, int v) { return sum[u] + sum[v] - 2 * sum[lca(u, v)]; }

 private:
  void dfs(int idx, int par, int d) {
    table[0][idx] = par;
    dep[idx] = d;
    for (auto &to : g[idx]) {
      if (to.first != par) {
        sum[to.first] = sum[idx] + to.second;
        dfs(to.first, idx, d + 1);
      }
    }
  }
};

template <typename T>
struct DSU {
  std::vector<T> f, siz;
  DSU(int n) : f(n), siz(n, 1) { std::iota(f.begin(), f.end(), 0); }
  T leader(T x) {
    while (x != f[x]) x = f[x] = f[f[x]];
    return x;
  }
  bool same(T x, T y) { return leader(x) == leader(y); }
  bool merge(T x, T y) {
    x = leader(x);
    y = leader(y);
    if (x == y) return false;
    siz[x] += siz[y];
    f[y] = x;
    return true;
  }
  T size(int x) { return siz[leader(x)]; }
};
// credit atcoder

// https://github.com/atcoder/ac-library/blob/master/document_en/mincostflow.md
namespace internal {

template <class T>
struct simple_queue {
  std::vector<T> payload;
  int pos = 0;
  void reserve(int n) { payload.reserve(n); }
  int size() const { return int(payload.size()) - pos; }
  bool empty() const { return pos == int(payload.size()); }
  void push(const T &t) { payload.push_back(t); }
  T &front() { return payload[pos]; }
  void clear() {
    payload.clear();
    pos = 0;
  }
  void pop() { pos++; }
};

}  // namespace internal

template <class Cap>
struct mf_graph {
 public:
  mf_graph() : _n(0) {}
  mf_graph(int n) : _n(n), g(n) {}

  int add_edge(int from, int to, Cap cap) {
    assert(0 <= from && from < _n);
    assert(0 <= to && to < _n);
    assert(0 <= cap);
    int m = int(pos.size());
    pos.push_back({from, int(g[from].size())});
    g[from].push_back(_edge{to, int(g[to].size()), cap});
    g[to].push_back(_edge{from, int(g[from].size()) - 1, 0});
    return m;
  }

  struct edge {
    int from, to;
    Cap cap, flow;
  };

  edge get_edge(int i) {
    int m = int(pos.size());
    assert(0 <= i && i < m);
    auto _e = g[pos[i].first][pos[i].second];
    auto _re = g[_e.to][_e.rev];
    return edge{pos[i].first, _e.to, _e.cap + _re.cap, _re.cap};
  }
  std::vector<edge> edges() {
    int m = int(pos.size());
    std::vector<edge> result;
    for (int i = 0; i < m; i++) {
      result.push_back(get_edge(i));
    }
    return result;
  }
  void change_edge(int i, Cap new_cap, Cap new_flow) {
    int m = int(pos.size());
    assert(0 <= i && i < m);
    assert(0 <= new_flow && new_flow <= new_cap);
    auto &_e = g[pos[i].first][pos[i].second];
    auto &_re = g[_e.to][_e.rev];
    _e.cap = new_cap - new_flow;
    _re.cap = new_flow;
  }

  Cap flow(int s, int t) { return flow(s, t, std::numeric_limits<Cap>::max()); }
  Cap flow(int s, int t, Cap flow_limit) {
    assert(0 <= s && s < _n);
    assert(0 <= t && t < _n);

    std::vector<int> level(_n), iter(_n);
    internal::simple_queue<int> que;

    auto bfs = [&]() {
      std::fill(level.begin(), level.end(), -1);
      level[s] = 0;
      que.clear();
      que.push(s);
      while (!que.empty()) {
        int v = que.front();
        que.pop();
        for (auto e : g[v]) {
          if (e.cap == 0 || level[e.to] >= 0) continue;
          level[e.to] = level[v] + 1;
          if (e.to == t) return;
          que.push(e.to);
        }
      }
    };
    auto dfs = [&](auto self, int v, Cap up) {
      if (v == s) return up;
      Cap res = 0;
      int level_v = level[v];
      for (int &i = iter[v]; i < int(g[v].size()); i++) {
        _edge &e = g[v][i];
        if (level_v <= level[e.to] || g[e.to][e.rev].cap == 0) continue;
        Cap d = self(self, e.to, std::min(up - res, g[e.to][e.rev].cap));
        if (d <= 0) continue;
        g[v][i].cap += d;
        g[e.to][e.rev].cap -= d;
        res += d;
        if (res == up) break;
      }
      return res;
    };

    Cap flow = 0;
    while (flow < flow_limit) {
      bfs();
      if (level[t] == -1) break;
      std::fill(iter.begin(), iter.end(), 0);
      while (flow < flow_limit) {
        Cap f = dfs(dfs, t, flow_limit - flow);
        if (!f) break;
        flow += f;
      }
    }
    return flow;
  }

  std::vector<bool> min_cut(int s) {
    std::vector<bool> visited(_n);
    internal::simple_queue<int> que;
    que.push(s);
    while (!que.empty()) {
      int p = que.front();
      que.pop();
      visited[p] = true;
      for (auto e : g[p]) {
        if (e.cap && !visited[e.to]) {
          visited[e.to] = true;
          que.push(e.to);
        }
      }
    }
    return visited;
  }

 private:
  int _n;
  struct _edge {
    int to, rev;
    Cap cap;
  };
  std::vector<std::pair<int, int>> pos;
  std::vector<std::vector<_edge>> g;
};

template <typename T>
struct FordFulkerson {
  struct Edge {
    int dst, rev;
    T cap;
    explicit Edge(const int dst, const T cap, const int rev)
        : dst(dst), rev(rev), cap(cap) {}
  };

  std::vector<std::vector<Edge>> graph;

  explicit FordFulkerson(const int n)
      : graph(n), timestamp(0), is_used(n, -1) {}

  void add_edge(const int src, const int dst, const T cap) {
    graph[src].emplace_back(dst, cap, graph[dst].size());
    graph[dst].emplace_back(src, 0, graph[src].size() - 1);
  }

  T maximum_flow(const int s, const int t,
                 T limit = std::numeric_limits<T>::max()) {
    T res = 0;
    while (limit > 0) {
      std::cout << "limit: " << limit << '\n';
      const T tmp = dfs(s, t, limit);
      ++timestamp;
      if (tmp == 0) break;
      limit -= tmp;
      res += tmp;
    }
    return res;
  }

 private:
  int timestamp;
  std::vector<int> is_used;

  T dfs(const int ver, const int t, const T flow) {
    if (ver == t) return flow;
    is_used[ver] = timestamp;
    for (Edge &e : graph[ver]) {
      if (is_used[e.dst] < timestamp && e.cap > 0) {
        const T tmp = dfs(e.dst, t, std::min(flow, e.cap));
        if (tmp > 0) {
          e.cap -= tmp;
          graph[e.dst][e.rev].cap += tmp;
          return tmp;
        }
      }
    }
    return 0;
  }
};

void solve() {
  int n, w;
  std::cin >> n >> w;
  std::vector<std::pair<int, int>> item(n);  // value, weights
  for (int i = 0; i < n; i++) {
    int a, b;
    std::cin >> a >> b;
    item[i] = {a, b};
  }
  long long ans = 0;
  std::sort(item.rbegin(), item.rend()); // sort items decreasing order in value
  std::vector dp(n + 1, std::vector<long long>(w + 1, 0));
  for (int i = 0; i < n; i++) {
    for (int j = 0; j <= w; j++) {
      auto [value, weight] = item[i];
      dp[i + 1][j] = std::max(dp[i + 1][j], dp[i][j]);

      if (j - weight >= 0) {
        if (dp[i + 1][j] < dp[i][j - weight] + value) {
          dp[i + 1][j] = dp[i][j - weight] + value;
          // item i is selected
          ans = std::max(ans, dp[i + 1][j] * value);
          // update our answer, we know the value is the minimum value in the
          // knapsack because of previous sorting
        }
      }
    }
  }

  std::cout << ans << '\n';
}

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);
  int t = 1;
  // std::cin >> t;

  while (t--) {
    solve();
  }
}