#include "bits/stdc++.h"

#define ALL(g) (g).begin(),(g).end()
#define REP(i, x, n) for(int i = x; i < n; i++)
#define rep(i,n) REP(i,0,n)
#define RREP(i, x, n) for(int i = x; i >= n; i--)
#define rrep(i, n) RREP(i,n,0)
#define pb push_back
#pragma GCC optimize ("-O3")

using namespace std;

#define DEBUG_IS_VALID 

#ifdef DEBUG_IS_VALID
#define DEB 1 
#else
#define DEB 0
#endif
#define DUMPOUT cout
#define dump(...) if(DEB) DUMPOUT<<"  "<<#__VA_ARGS__<<" :["<<__LINE__<<":"<<__FUNCTION__<<"]"<<endl<<"    "; if(DEB) dump_func(__VA_ARGS__)
template<typename T1,typename T2>ostream& operator << (ostream& os, pair<T1,T2> p){cout << "(" << p.first << ", " << p.second << ")"; return os;}
template<typename T>ostream& operator << (ostream& os, vector<T>& vec) { os << "{"; for (int i = 0; i<vec.size(); i++) os << vec[i] << (i + 1 == vec.size() ? "" : ", "); os << "}"; return os; }
template<typename T>ostream& operator << (ostream& os, set<T>& st){cout << "{"; for(auto itr = st.begin(); itr != st.end(); itr++) cout << *itr << (next(itr)!=st.end() ? ", " : ""); cout << "}"; return os;}
template<typename T1,typename T2>ostream& operator << (ostream& os, map<T1,T2> mp){cout << "{"; for(auto itr = mp.begin(); itr != mp.end(); itr++) cout << "(" << (itr->first) << ", " << (itr->second) << ")" << (next(itr)!=mp.end() ? "," : ""); cout << "}"; return os; }

void dump_func(){DUMPOUT << endl;}
template <class Head, class... Tail>void dump_func(Head&& head, Tail&&... tail){ DUMPOUT << head; if (sizeof...(Tail) == 0) { DUMPOUT << " "; } else { DUMPOUT << ", "; } dump_func(std::move(tail)...);}
template<class T> inline bool chmax(T& a,T const& b){if(a>=b) return false; a=b; return true;}
template<class T> inline bool chmin(T& a,T const& b){if(a<=b) return false; a=b; return true;}
void _main();
int main(){ cin.tie(0); ios::sync_with_stdio(false); _main(); return 0;}

using ll = long long;
using P = pair<int,int>;
using Pl = pair<ll,ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;

const int mod=1e9+7,INF=1<<29;
const double EPS=1e-5,PI=3.1415926535897932384626;
const ll lmod = 1e9+7,LINF=1LL<<59; 

int dp[51][53][53][51];

void _main(){
  int N; cin >> N ;
  int C; cin >> C ;
  rep(i,N+1) rep(j,N+1) rep(k,N+1) rep(l,51) dp[i][j][k][l] = -INF;
  vi L(N),W(N);
  rep(i,N) cin >> L[i] ;
  rep(i,N) cin >> W[i] ;
  rep(j,N) rep(k,N) if(W[j]+W[k]<=C && L[j]!=L[k]) dp[0][j][k][W[j]+W[k]] = L[j] + L[k];
  int cnt = 0;
  bool update;
  int ans = 0;
  rep(i,50){
    update = false;
    int ma  = 0;
    rep(j,N) rep(k,N) rep(c,C) rep(l,N){
      if(L[j]==L[l] || L[k]==L[l] || L[j]==L[k]) continue;
      if(c+W[l]>C) continue;
      if(!((L[k]>L[j]&&L[k]>L[l])||(L[k]<L[j]&&L[k]<L[l]))) continue;
      if(dp[i][j][k][c]==-INF) continue;
      if(chmax(dp[i+1][k][l][c+W[l]],dp[i][j][k][c]+L[l])){
        // cout << i << " " << j << " " << k << " " << l << " " << dp[i+1][k][l][c+W[l]] << endl;
        update = true;
        chmax(ans,dp[i+1][k][l][c+W[l]]);
      }
    }
    if(!update){
      cnt = i;
      break;
    }
  }
  cout << ans << endl;
}