#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 debugm(m) printf("L%d %s is..\n",__LINE__,#m);for(auto v:m){for(auto e:v){cout<<e<<" ";}cout<<endl;}
#define debuga(m,w) printf("L%d %s is => ",__LINE__,#m);for(int x=0;x<(w);x++){cout<<(m)[x]<<" ";}cout<<endl;
#define debugaa(m,w,h) printf("L%d %s is..\n",__LINE__,#m);for(int y=0;y<(h);y++){for(int x=0;x<(w);x++){cout<<(m)[x][y]<<" ";}cout<<endl;}
#define debugaar(m,w,h) printf("L%d %s is..\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(l) for(auto cnt=0;cnt<(l);++cnt)
#define iterate(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; }

#define TIME chrono::system_clock::now()
#define MILLISEC(t) (chrono::duration_cast<chrono::milliseconds>(t).count())
namespace {
    std::chrono::system_clock::time_point ttt;
    void tic() { ttt = TIME; }
    void toc() { fprintf(stderr, "TIME : %lldms\n", MILLISEC(TIME - ttt)); }
    std::chrono::system_clock::time_point tle = TIME;
#ifdef __MAI
    void safe_tle(int msec) { assert(MILLISEC(TIME - tle) < msec); }
#else
#define safe_tle(k) ;
#endif
}

#ifdef __MAI
#define getchar_unlocked getchar
#define putchar_unlocked putchar
#endif
#ifdef __VSCC
#define getchar_unlocked _getchar_nolock
#define putchar_unlocked _putchar_nolock
#endif
namespace {
#define isvisiablechar(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 (; !isvisiablechar(cc); cc = getchar_unlocked());
            for (; isvisiablechar(cc); cc = getchar_unlocked())
                var.push_back(cc);
        }
    };
}
MaiScanner scanner;


// -----------------------------------------------------------------------
// ここから！
// -----------------------------------------------------------------------


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



int n, cap;

int price[111], len[111];

// TODO: N<3を得てしまうので，個数を数えてごまかす
// TODO: 落とせるかも？
// 
int dfs(int cost = 0, int pre = 0, int prepre = 0) {
    static unordered_map<int, int> dp;

    int key = (cost << 24) | (pre << 8) | prepre;
    if (dp.count(key)) return dp[key];

    int best = 0;

    for (int i = 0; i < n; ++i) {
        if (cost + price[i] > cap) continue;
        if (prepre == 0 || kadomatu(len[i], pre, prepre)) {
            best = max(best, dfs(cost + price[i], len[i], pre) + len[i]);
        }
    }
    return best;
}

int dp[51][51][51];
int main() {

    scanner >> n >> cap;

    repeat(n) {
        scanner >> len[cnt];
    }

    repeat(n) {
        scanner >> price[cnt];
    }

    // cout << dfs() << endl;

    int result = 0;

    for (int i = 0; i < n; ++i) {
        if (price[i] <= cap)
            dp[price[i]][len[i]][0] = len[i];
    }

    for (int cost = 0; cost < cap; ++cost) {
        for (int pre = 0; pre <= 50; ++pre) {
            for (int prepre = 0; prepre <= 50; ++prepre) {
                for (int i = 0; i < n; ++i) {
                    if (cost + price[i] > cap) continue;
                    if (dp[cost][pre][prepre] == 0) continue;

                    if (prepre == 0 || kadomatu(len[i], pre, prepre)) {
                        dp[cost + price[i]][len[i]][pre]
                            = max(
                                dp[cost + price[i]][len[i]][pre],
                                dp[cost][pre][prepre] + len[i]);

                        if (prepre != 0)
                            result = max(result, dp[cost + price[i]][len[i]][pre]);
                    }
                }
            }
        }
    }

    cout << result << endl;


    return 0;
}