#include <bits/stdc++.h>
using namespace std;
namespace mine {
long long qread() {
  long long ans = 0, f = 1;
  char c = getchar();
  while (c < '0' or c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while ('0' <= c and c <= '9') ans = ans * 10 + c - '0', c = getchar();
  return ans * f;
}
void write(long long num) {
  if (num < 0) putchar('-'), num = -num;
  if (num >= 10) write(num / 10);
  putchar('0' + num % 10);
}
void write1(long long num) {
  write(num);
  putchar(' ');
}
void write2(long long num) {
  write(num);
  putchar('\n');
}
template <typename T>
inline bool chmax(T &a, const T &b) {
  return a < b ? a = b, 1 : 0;
}
template <typename T>
inline bool chmin(T &a, const T &b) {
  return a > b ? a = b, 1 : 0;
}
long long gcd(long long x, long long y) { return y ? gcd(y, x % y) : x; }
bool IN(long long x, long long l, long long r) { return l <= x and x <= r; }
void gg() {
  write2(-1);
  exit(0);
}
const double eps = 1e-8;
const int INF = 0x3f3f3f3f;
const int MOD = 998244353;
int mm(const int x) { return x >= MOD ? x - MOD : x; }
template <typename T>
void add(T &x, const int &y) {
  x = (x + y >= MOD ? x + y - MOD : x + y);
}
long long qpower(long long x, long long e, int mod = MOD) {
  long long ans = 1;
  while (e) {
    if (e & 1) ans = ans * x % mod;
    x = x * x % mod;
    e >>= 1;
  }
  return ans;
}
long long invm(long long x) { return qpower(x, MOD - 2); }
const int N = 5e1 + 10;
int n;
pair<long long, long long> a[N];
bool cmp(pair<long long, long long> x, pair<long long, long long> y) {
  return x.first > y.first or (x.first == y.first and x.second < y.second);
}
long long dp[N][N][2];
bool check(long long T) {
  memset(dp, 0x3f, sizeof dp);
  dp[0][0][0] = 0;
  for (int i = (1), I = (n); i <= I; i++)
    for (int sum = (0), I = (i); sum <= I; sum++)
      for (int lst = (0), I = (1); lst <= I; lst++) {
        long long val = a[i].first - T * a[i].second;
        if (sum - 1 >= 0 and (a[i - 1].first != a[i].first or lst))
          chmin(dp[i][sum - 1][1], dp[i - 1][sum][lst]);
        chmin(dp[i][sum + 1][0], dp[i - 1][sum][lst] + val);
      }
  if (T < 1688)
    if (0) printf("line %d\n", 103);
  for (int sum = (0), I = (n); sum <= I; sum++)
    for (int lst = (0), I = (1); lst <= I; lst++)
      if (dp[n][sum][lst] <= 0) return 1;
  return 0;
}
void main() {
  n = qread();
  for (int i = (1), I = (n); i <= I; i++) a[i].first = qread() * 1000;
  for (int i = (1), I = (n); i <= I; i++) a[i].second = qread();
  sort(a + 1, a + n + 1, cmp);
  long long L = 0, R = 1e13, ans = -1;
  while (L <= R) {
    long long mid = (L + R) / 2;
    if (check(mid))
      ans = mid, R = mid - 1;
    else
      L = mid + 1;
  }
  write(ans);
}
};  // namespace mine
signed main() {
  srand(time(0));
  mine::main();
}
