#include <bits/stdc++.h>
using namespace std;
#define int long long
#define stoi stoll
using ll=long long;
using vi=vector<int>;
using pii=pair<int,int>;
#define ALL(c) begin(c),end(c)
#define RALL(c) rbegin(c),rend(c)
#define ITR(i,b,e) for(auto i=(b);i!=(e);++i)
#define FORE(x,c) for(auto &&x:c)
#define REPF(i,a,n) for(int i=a,i##len=(int)(n);i<i##len;++i)
#define REP(i,n) REPF(i,0,n)
#define REPR(i,n) for(int i=(int)(n);i>=0;--i)
#define SZ(c) ((int)c.size())
#define CONTAIN(c,x) (c.find(x)!=end(c))
#define INSEG(l,x,r) ((l)<=(x)&&(x)<(r))
#define dump(...)
#define pb push_back
#define _ 0
const signed INF_=1001001001; const long long INF=1001001001001001001LL;
const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0};
template<class T> ostream& operator<<(ostream &os,const vector<T> &v) {
    ITR(i,begin(v),end(v))os<<*i<<(i==end(v)-1?"":" ");return os;}
template<class T> istream& operator>>(istream &is,vector<T> &v) {
    ITR(i,begin(v),end(v)) is>>*i;return is;}
template<class T,class U> istream& operator>>(istream &is, pair<T,U> &p) {
    is>>p.first>>p.second;return is;}
template<class T, class U> bool chmax(T &a,const U &b){return a<b?a=b,1:0;}
template<class T, class U> bool chmin(T &a,const U &b){return a>b?a=b,1:0;}
template <class T> void PSUM(T& c) {partial_sum(begin(c), end(c), begin(c));}
template<class T> using heap=priority_queue<T,vector<T>,greater<T>>;
struct before_main_function {
    before_main_function() {
        cin.tie(0); ios::sync_with_stdio(false);
        cout << setprecision(15) << fixed;
        // #define endl "\n"
    }
} before_main_function;
//------------------8<------------------------------------8<--------------------

int N, C;
int L[51], W[51];
int dp[2][51][51][110];
int rec(bool ord, int last1, int last2, int yen) {
    auto &DP = dp[ord][last1][last2][yen];
    if (DP != -1) return DP;

    int ret = 0;
    REP(i, N) {
        if ((ord && last1 <= L[i]) || (!ord && last1 >= L[i])) continue;
        if (last2 == L[i]) continue;
        int r = yen - W[i];
        if (r >= 0)
            chmax(ret, rec(ord ^ 1, L[i], last1, r) + L[i]);
    }
    return DP = ret;
}
signed main() {
    REP(i, 2) REP(j, 51) REP(k, 51) REP(l, 110) dp[i][j][k][l] = -1;
    cin >> N >> C;
    REP(i, N) cin >> L[i];
    REP(i, N) cin >> W[i];
    int ans = 0;
    REP(i, N) {
        REP(j, N) {
            if (L[i] == L[j]) continue;
            int res = rec(L[i] < L[j], L[j], L[i], C - W[i] - W[j]);
            if (res > 0) chmax(ans, rec(L[i] < L[j], L[j], L[i], C - W[i] - W[j]) + L[i] + L[j]);
        }
    }
    cout << ans << endl;
    return (0^_^0);
}