#include <bits/stdc++.h>

using namespace std;

using int64 = long long;
const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in : v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e : t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

int main() {
  int N;
  cin >> N;
  vector< int > A(N + 1), B(N + 1), D(N);
  cin >> A >> B >> D;
  sort(begin(D), end(D));
  auto mat = make_v< int >(N + 1, N + 1);
  for(int i = 0; i <= N; i++) {
    for(int j = 0; j <= N; j++) {
      mat[i][j] = upper_bound(begin(D), end(D), A[i] + B[j]) - begin(D);
      mat[i][j]--;
    }
  }

  auto check = [&](int x) {
    auto dp = make_v< int >(N + 2, N + 2);
    fill_v(dp, -1);
    auto rec = MFP([&](auto rec, int x, int y, int t) -> int {
      if(t < 0) return 0;
      if(~dp[x][y]) return dp[x][y];
      int ret = 0;
      if(x < N) chmax(ret, rec(x + 1, y, t - 1) + (mat[x + 1][y] >= t));
      if(y < N) chmax(ret, rec(x, y + 1, t - 1) + (mat[x][y + 1] >= t));
      return dp[x][y] = ret;
    });
    return rec(0, 0, x - 1) >= x;
  };

  int ok = 0, ng = N + 1;
  while(ng - ok > 1) {
    int mid = (ok + ng) / 2;
    if(check(mid)) ok = mid;
    else ng = mid;
  }
  cout << ok << endl;

}