#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

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

int main() {
  constexpr int M = 50;
  int n, c; cin >> n >> c;
  vector<int> l(n), w(n);
  REP(i, n) cin >> l[i];
  REP(i, n) cin >> w[i];
  vector<int> cost(M + 1, INF);
  REP(i, n) chmin(cost[l[i]], w[i]);
  map<tuple<int, int, int>, int> dp;
  FOR(i, 1, M + 1) FOR(j, 1, M + 1) {
    if (cost[i] + cost[j] < c && i != j) chmax(dp[{c - (cost[i] + cost[j]), i, j}], i + j);
  }
  int ans = 0;
  while (!dp.empty()) {
    map<tuple<int, int, int>, int> nx;
    for (auto [ijk, v] : dp) {
      auto [i, j, k] = ijk;
      FOR(x, 1, M + 1) {
        if (cost[x] <= i && is_kadomatsu(j, k, x)) {
          chmax(ans, v + x);
          if (cost[x] < i) chmax(nx[{i - cost[x], k, x}], v + x);
        }
      }
    }
    dp.swap(nx);
  }
  cout << ans << '\n';
  return 0;
}