#include <bits/stdc++.h>
#define range(i, l, r) for(int (i) = (l); (i) < (r); (i)++)
#define reversed_range(i, l, r) for (int (i) = (r) - 1; (i) >= l; (i)--)
using namespace std;
template <typename T>
using vec = vector<T>;
using lint = long long;
using ulint = unsigned long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;

template <typename S, typename T>
ostream& operator <<(ostream& os, pair<S, T> p) {
    os << "(";
    os << p.first << ", " << p.second;
    return os << ")";
}

template <typename T>
ostream& operator <<(ostream& os, vec<T> v) {
    os << "[";
    for (int i = 0; i < v.size() - 1; i++) {
        os << v.at(i) << ", ";
    }
    return os << v.at(v.size() - 1) << "]";
}

template <typename T>
ostream& operator <<(ostream& os, set<T>& s) {
    os << "{";
    auto it_first_item = s.begin();
    cout << *it_first_item;
    for (auto it = ++it_first_item; it != s.end(); it++) {
        cout << ", " << *it;
    }
    return cout << "}";
}

template <typename T>
ostream& operator <<(ostream& os, unordered_set<T>& s) {
    os << "{";
    auto it_first_item = s.begin();
    cout << *it_first_item;
    for (auto it = ++it_first_item; it != s.end(); it++) {
        cout << ", " << *it;
    }
    return cout << "}";
}

template <typename K, typename V>
ostream& operator <<(ostream& os, map<K, V> m) {
    os << "{";
    auto it_first_item = m.begin();
    if (m.begin() == m.end()) return os << "}";
    cout << it_first_item->first << ": " << it_first_item->second;
    for (auto it = ++it_first_item; it != m.end(); it++) {
        cout << ", " << it->first << ": " << it->second;
    }
    return os << "}";
}

template <typename K, typename V>
ostream& operator <<(ostream& os, unordered_map<K, V> m) {
    os << "{";
    auto it_first_item = m.begin();
    cout << it_first_item->first << ": " << it_first_item->second;
    for (auto it = ++it_first_item; it != m.end(); it++) {
        cout << ", " << it->first << ": " << it->second;
    }
    return os << "}";
}

lint pow(lint num, lint e, lint MOD) {
    lint res = 1;
    lint cur_num = num;
    while (e) {
        if (e & 1) {
            res *= cur_num;
            res %= MOD;
        }
        cur_num *= cur_num;
        cur_num %= MOD;
        e >>= 1;
    }
    return res;
}

int main() {
    cin.tie(0); cout.tie(0);
    ios::sync_with_stdio(false);
    lint N, W;
    cin >> N >> W;
    vec<plint> items(N);
    range(i, 0, N) {
        lint w, v;
        cin >> w >> v;
        items.at(i) = {w, v};
    }
    vec<map<lint, lint>> dp(N + 1, map<lint, lint>());
    dp.at(0).emplace(0, 0);
    range(i, 0, N) {
        lint wn = items.at(i).first, vn = items.at(i).second;
        for (const auto pair : dp.at(i)) dp.at(i + 1).emplace(pair.first, pair.second);
        for (const auto pair : dp.at(i)) {
            lint w = pair.first, v = pair.second;
            if (w + wn <= W) {
                if (dp.at(i + 1).find(w + wn) == dp.at(i + 1).end()) dp.at(i + 1).emplace(w + wn, v + vn);
                else dp.at(i + 1).at(w + wn) = max(dp.at(i + 1).at(w + wn), v + vn);
            }
        }
    }
    // cout << dp << "\n";
    lint max_sum_value = 0;
    for (const auto pair : dp.at(N)) {
        max_sum_value = max(max_sum_value, pair.second);
    }
    cout << max_sum_value << "\n";
}

Measured memory_bytes: 6528