#include <bits/stdc++.h>
#define rep(i, n) for (ll i = 0; i < (ll)(n); ++i)
#define rep2(i, s, n) for (ll i = s; i < (ll)(n); i++)
#define repr(i, n) for (ll i = n; i >= 0; i--)
#define pb push_back
#define COUT(x) cout << (x) << "\n"
#define COUTF(x) cout << setprecision(15) << (x) << "\n"
#define ENDL cout << "\n"
#define DF(x) x.erase(x.begin())
#define ALL(x) x.begin(), x.end()
#define SORT(x) sort(ALL(x))
#define RSORT(x) sort(x.rbegin(), x.rend())
#define REVERSE(x) reverse(ALL(x))
#define MAX(x) *max_element(ALL(x))
#define MAXI(x) max_element(ALL(x)) - x.begin()
#define SUM(x) accumulate(ALL(x), 0)
#define COUNT(x, y) count(ALL(x), y);
#define ANS cout << ans << "\n"
#define YES cout << "YES\n";
#define NO cout << "NO\n";
#define Yes cout << "Yes\n";
#define No cout << "No\n";
#define YN YES else NO
#define yn Yes else No
#define init() \
  cin.tie(0);  \
  ios::sync_with_stdio(false)
#define LINE cerr << "[debug] line: " << __LINE__ << "\n";
#define debug(x) cerr << "[debug] " << #x << ": " << x << "\n";
#define debugV(v)                       \
  cerr << "[debugV] " << #v << ":";     \
  rep(z, v.size()) cerr << " " << v[z]; \
  cerr << "\n";
using namespace std;
using ll = long long;
using ld = long double;
using vll = vector<ll>;
using vvll = vector<vector<ll>>;
using mll = map<ll, ll>;
using qll = queue<ll>;
using P = pair<ll, ll>;
using vp = vector<P>;
using vs = vector<string>;

template <typename T>
inline istream& operator>>(istream& i, vector<T>& v) {
  rep(j, v.size()) i >> v[j];
  return i;
}

template <typename T1, typename T2>
inline istream& operator>>(istream& i, pair<T1, T2>& v) {
  return i >> v.first >> v.second;
}

constexpr ll INF = 0x3f3f3f3f3f3f3f3f;
constexpr ld PI = 3.141592653589793238462643383279;
ll get_digit(ll x) {
  return to_string(x).size();
}

ll gcd(ll x, ll y) {
  return y ? gcd(y, x % y) : x;
}

ll lcm(ll a, ll b) {
  return a / gcd(a, b) * b;
}

template <class T>
bool chmax(T& a, const T& b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}

template <class T>
bool chmin(T& a, const T& b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

struct ABCD {
  ll a;
  ll b;
  ll c;
  ll d;
};

signed main() {
  init();
  ll N, W;
  cin >> N >> W;

  ll w1 = 0;
  map<tuple<ll, ll, ll, ll>, ll> m;
  m[{0, 0, 0, 0}] = 0;
  rep(i, N) {
    ll w, v;
    cin >> w >> v;
    if (i == 0) w1 = w;
    map<tuple<ll, ll, ll, ll>, ll> next;
    for (auto mm : m) {
      tuple<ll, ll, ll, ll> f = mm.first;
      ll a = get<0>(f);
      ll b = get<1>(f);
      ll c = get<2>(f);
      ll d = get<3>(f);

      ll weight = a * w1 + b * (w1 + 1) + c * (w1 + 2) + d * (w1 + 3);
      if (weight > W) continue;

      if (next[{a, b, c, d}] < mm.second) next[{a, b, c, d}] = mm.second;

      if (w == w1 and next[{a + 1, b, c, d}] < mm.second + v)
        next[{a + 1, b, c, d}] = mm.second + v;

      if (w == w1 + 1 and next[{a, b + 1, c, d}] < mm.second + v)
        next[{a, b + 1, c, d}] = mm.second + v;

      if (w == w1 + 2 and next[{a, b, c + 1, d}] < mm.second + v)
        next[{a, b, c + 1, d}] = mm.second + v;

      if (w == w1 + 3 and next[{a, b, c, d + 1}] < mm.second + v)
        next[{a, b, c, d + 1}] = mm.second + v;
    }
    m = next;
  }

  ll ans = 0;
  for (auto mm : m) {
    tuple<ll, ll, ll, ll> f = mm.first;
    ll a = get<0>(f);
    ll b = get<1>(f);
    ll c = get<2>(f);
    ll d = get<3>(f);
    ll weight = a * w1 + b * (w1 + 1) + c * (w1 + 2) + d * (w1 + 3);
    if (weight <= W) chmax(ans, mm.second);
  }
  ANS;
  return 0;
}

Measured memory_bytes: 31664