#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#include "bits/stdc++.h" // define macro "/D__MAI"

using namespace std;
typedef long long int ll;

#define debugv(v) {printf("L%d %s > ",__LINE__,#v);for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) {printf("L%d %s > ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;}
#define debugaa(m,h,w) {printf("L%d %s >\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[y][x]<<" ";}cout<<endl;}}
#define ALL(v) (v).begin(),(v).end()
#define repeat(cnt,l) for(auto cnt=0ll;(cnt)<(l);++(cnt))
#define rrepeat(cnt,l) for(auto cnt=(l)-1;0<=(cnt);--(cnt))
#define iterate(cnt,b,e) for(auto cnt=(b);(cnt)!=(e);++(cnt))
#define MD 1000000007ll
#define PI 3.1415926535897932384626433832795
template<typename T1, typename T2> ostream& operator <<(ostream &o, const pair<T1, T2> p) { o << "(" << p.first << ":" << p.second << ")"; return o; }
template<typename T> T& maxset(T& to, const T& val) { return to = max(to, val); }
template<typename T> T& minset(T& to, const T& val) { return to = min(to, val); }
void bye(string s, int code = 0) { cout << s << endl; exit(0); }
mt19937_64 randdev(8901016);
inline ll rand_range(ll l, ll h) {
    return uniform_int_distribution<ll>(l, h)(randdev);
}

#if defined(_WIN32) || defined(_WIN64)
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#elif __GNUC__
#else
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
namespace {
#define isvisiblechar(c) (0x21<=(c)&&(c)<=0x7E)
    class MaiScanner {
    public:
        template<typename T> void input_integer(T& var) {
            var = 0; T sign = 1;
            int cc = getchar_unlocked();
            for (; cc<'0' || '9'<cc; cc = getchar_unlocked())
                if (cc == '-') sign = -1;
            for (; '0' <= cc && cc <= '9'; cc = getchar_unlocked())
                var = (var << 3) + (var << 1) + cc - '0';
            var = var * sign;
        }
        inline int c() { return getchar_unlocked(); }
        inline MaiScanner& operator>>(int& var) { input_integer<int>(var); return *this; }
        inline MaiScanner& operator>>(long long& var) { input_integer<long long>(var); return *this; }
        inline MaiScanner& operator>>(string& var) {
            int cc = getchar_unlocked();
            for (; !isvisiblechar(cc); cc = getchar_unlocked());
            for (; isvisiblechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
        }
        template<typename IT> void in(IT begin, IT end) { for (auto it = begin; it != end; ++it) *this >> *it; }
    };
    class MaiPrinter {
    public:
        template<typename T>
        void output_integer(T var) {
            if (var == 0) { putchar_unlocked('0'); return; }
            if (var < 0)
                putchar_unlocked('-'),
                var = -var;
            char stack[32]; int stack_p = 0;
            while (var)
                stack[stack_p++] = '0' + (var % 10),
                var /= 10;
            while (stack_p)
                putchar_unlocked(stack[--stack_p]);
        }
        inline MaiPrinter& operator<<(char c) { putchar_unlocked(c); return *this; }
        inline MaiPrinter& operator<<(int var) { output_integer<int>(var); return *this; }
        inline MaiPrinter& operator<<(long long var) { output_integer<long long>(var); return *this; }
        inline MaiPrinter& operator<<(char* str_p) { while (*str_p) putchar_unlocked(*(str_p++)); return *this; }
        inline MaiPrinter& operator<<(const string& str) {
            const char* p = str.c_str();
            const char* l = p + str.size();
            while (p < l) putchar_unlocked(*p++);
            return *this;
        }
        template<typename IT> void join(IT begin, IT end, char sep = '\n') { for (auto it = begin; it != end; ++it) *this << *it << sep; }
    };
}
MaiScanner scanner;
MaiPrinter printer;


// =================================================================
// =================================================================


struct bamboo {
    bamboo(int l = 0, int w = 0) {}
    int length;
    int price;
};
ostream& operator <<(ostream &o, const bamboo p) { o << make_pair(p.length, p.price); return o; }


inline bool iskadomatsu(int a, int b, int c) {
    return a!=c && ((a<b && b>c)||(a>b && b<c));
}


int n, capacity;
vector<bamboo> bb;


// DP配列
// dp[重さ][直前の直前の竹の長さ][直前の竹の長さ]
int dp[55][55][55];

int main() {

    // 読み込み
    scanner >> n >> capacity;
    if (n <= 2) bye("0");

    bb.resize(n);
    repeat(i, n) {
        scanner >> bb[i].length;
    }
    repeat(i, n) {
        scanner >> bb[i].price;
    }


    int answer = 0;


    // 1番目に選ぶ竹
    for (int i = 0; i < n; ++i) {

        // 2番目に選ぶ竹
        for (int j = 0; j < n; ++j) {

            // 隣り合う竹の長さが同じ場合，門松列列の条件は満たさない．
            if (bb[i].length == bb[j].length) continue;

            // 予算が足りない
            if (bb[i].price + bb[j].price > capacity) continue;

            // 
            maxset(
                dp[bb[i].price + bb[j].price][bb[i].length][bb[j].length],
                bb[i].length + bb[j].length
            );
        }
    }


    // w円を既に消費した
    for (int w = 2; w < capacity; ++w) {

        // 番号iの竹を買おうとしている
        for (int i = 0; i < n; ++i) {

            // 予算が足りないなら遷移しない
            if (w + bb[i].price > capacity) continue;

            // もし直前の直前に選んだ竹の長さがl1，直前に選んだ竹の長さがl2ならば
            for (int l1 = 1; l1 <= 50; ++l1) {
                for (int l2 = 1; l2 <= 50; ++l2) {

                    // 門松列列の条件を満たしていないので遷移しない
                    if (!iskadomatsu(l1, l2, bb[i].length)) continue;

                    // そのような状況は存在しないので遷移しない
                    if (dp[w][l1][l2] == 0) continue;

                    // 
                    maxset(
                        dp[w + bb[i].price][l2][bb[i].length],
                        dp[w][l1][l2] + bb[i].length
                    );

                    maxset(answer, dp[w][l1][l2] + bb[i].length);
                }
            }

        }
        
    }


    printer << answer << '\n';




    return 0;
}