import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.util.Arrays;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.io.Closeable;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) throws Exception {
        Thread thread = new Thread(null, new TaskAdapter(), "", 1 << 27);
        thread.start();
        thread.join();
    }

    static class TaskAdapter implements Runnable {
        @Override
        public void run() {
            InputStream inputStream = System.in;
            OutputStream outputStream = System.out;
            FastInput in = new FastInput(inputStream);
            FastOutput out = new FastOutput(outputStream);
            DComputePower solver = new DComputePower();
            solver.solve(1, in, out);
            out.close();
        }
    }

    static class DComputePower {
        Debug debug = new Debug(true);

        public void solve(int testNumber, FastInput in, FastOutput out) {
            int n = in.readInt();
            Task[] tasks = new Task[n + 1];
            for (int i = 1; i <= n; i++) {
                tasks[i] = new Task();
                tasks[i].a = in.readInt();
            }

            int bSum = 0;
            for (int i = 1; i <= n; i++) {
                tasks[i].b = in.readInt();
                bSum += tasks[i].b;
            }

            Arrays.sort(tasks, 1, n + 1, (a, b) -> a.a == b.a ? -Long.compare(a.b, b.b) : -Long.compare(a.a, b.a));
            long[][][] dp = new long[n + 1][n + 1][bSum + 1];
            long inf = (long) 1e15;
            SequenceUtils.deepFill(dp, (long) inf);
            dp[0][0][0] = 0;
            for (int i = 1; i <= n; i++) {
                int r = i;
                while (r + 1 <= n && tasks[r + 1].a == tasks[i].a) {
                    r++;
                }
                int m = r - i + 1;
                long[] prefixA = new long[m + 1];
                int[] prefixB = new int[m + 1];
                for (int j = 0; j < m; j++) {
                    prefixA[j + 1] = tasks[i + j].a;
                    prefixB[j + 1] = tasks[i + j].b;
                }
                LongPreSum aPs = new LongPreSum(prefixA);
                IntegerPreSum bPs = new IntegerPreSum(prefixB);

                for (int t = 0; t <= m; t++) {
                    int frontCnt = t;
                    int backCnt = m - t;
                    long frontA = aPs.prefix(t);
                    int frontB = bPs.prefix(t);

                    for (int j = 0; j <= n; j++) {
                        for (int k = 0; k <= bSum; k++) {
                            // add as first
                            if (j >= backCnt && j - backCnt + frontCnt <= n && k + frontB <= bSum) {
                                dp[r][j - backCnt + frontCnt][k + frontB] = Math.min(dp[r][j - backCnt + frontCnt][k + frontB], dp[i - 1][j][k] + frontA);
                            }
                        }
                    }
                }
            }


            debug.debug("dp", dp);
            long min = inf;
            for (int i = 0; i <= n; i++) {
                for (int j = 1; j <= bSum; j++) {
                    min = Math.min(min, DigitUtils.ceilDiv(dp[n][i][j] * 1000, j));
                }
            }

            out.println(min);
        }

    }

    static class LongPreSum {
        private long[] pre;
        private int n;

        public LongPreSum(int n) {
            pre = new long[n];
        }

        public void populate(long[] a) {
            n = a.length;
            pre[0] = a[0];
            for (int i = 1; i < n; i++) {
                pre[i] = pre[i - 1] + a[i];
            }
        }

        public LongPreSum(long[] a) {
            this(a.length);
            populate(a);
        }

        public long prefix(int i) {
            if (i < 0) {
                return 0;
            }
            return pre[Math.min(i, n - 1)];
        }

    }

    static class FastInput {
        private final InputStream is;
        private byte[] buf = new byte[1 << 20];
        private int bufLen;
        private int bufOffset;
        private int next;

        public FastInput(InputStream is) {
            this.is = is;
        }

        private int read() {
            while (bufLen == bufOffset) {
                bufOffset = 0;
                try {
                    bufLen = is.read(buf);
                } catch (IOException e) {
                    bufLen = -1;
                }
                if (bufLen == -1) {
                    return -1;
                }
            }
            return buf[bufOffset++];
        }

        public void skipBlank() {
            while (next >= 0 && next <= 32) {
                next = read();
            }
        }

        public int readInt() {
            int sign = 1;

            skipBlank();
            if (next == '+' || next == '-') {
                sign = next == '+' ? 1 : -1;
                next = read();
            }

            int val = 0;
            if (sign == 1) {
                while (next >= '0' && next <= '9') {
                    val = val * 10 + next - '0';
                    next = read();
                }
            } else {
                while (next >= '0' && next <= '9') {
                    val = val * 10 - next + '0';
                    next = read();
                }
            }

            return val;
        }

    }

    static class SequenceUtils {
        public static void deepFill(Object array, long val) {
            if (!array.getClass().isArray()) {
                throw new IllegalArgumentException();
            }
            if (array instanceof long[]) {
                long[] longArray = (long[]) array;
                Arrays.fill(longArray, val);
            } else {
                Object[] objArray = (Object[]) array;
                for (Object obj : objArray) {
                    deepFill(obj, val);
                }
            }
        }

    }

    static class IntegerPreSum {
        private int[] pre;
        private int n;

        public IntegerPreSum(int n) {
            pre = new int[n];
        }

        public void populate(int[] a) {
            n = a.length;
            pre[0] = a[0];
            for (int i = 1; i < n; i++) {
                pre[i] = pre[i - 1] + a[i];
            }
        }

        public IntegerPreSum(int[] a) {
            this(a.length);
            populate(a);
        }

        public int prefix(int i) {
            if (i < 0) {
                return 0;
            }
            return pre[Math.min(i, n - 1)];
        }

    }

    static class DigitUtils {
        private DigitUtils() {
        }

        public static long floorDiv(long a, long b) {
            return a < 0 ? -ceilDiv(-a, b) : a / b;
        }

        public static long ceilDiv(long a, long b) {
            if (a < 0) {
                return -floorDiv(-a, b);
            }
            long c = a / b;
            if (c * b < a) {
                return c + 1;
            }
            return c;
        }

    }

    static class Task {
        long a;
        int b;

    }

    static class FastOutput implements AutoCloseable, Closeable, Appendable {
        private StringBuilder cache = new StringBuilder(10 << 20);
        private final Writer os;

        public FastOutput append(CharSequence csq) {
            cache.append(csq);
            return this;
        }

        public FastOutput append(CharSequence csq, int start, int end) {
            cache.append(csq, start, end);
            return this;
        }

        public FastOutput(Writer os) {
            this.os = os;
        }

        public FastOutput(OutputStream os) {
            this(new OutputStreamWriter(os));
        }

        public FastOutput append(char c) {
            cache.append(c);
            return this;
        }

        public FastOutput append(long c) {
            cache.append(c);
            return this;
        }

        public FastOutput println(long c) {
            return append(c).println();
        }

        public FastOutput println() {
            cache.append(System.lineSeparator());
            return this;
        }

        public FastOutput flush() {
            try {
                os.append(cache);
                os.flush();
                cache.setLength(0);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
            return this;
        }

        public void close() {
            flush();
            try {
                os.close();
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }
        }

        public String toString() {
            return cache.toString();
        }

    }

    static class Debug {
        private boolean offline;
        private PrintStream out = System.err;
        static int[] empty = new int[0];

        public Debug(boolean enable) {
            offline = enable && System.getSecurityManager() == null;
        }

        public Debug debug(String name, Object x) {
            return debug(name, x, empty);
        }

        public Debug debug(String name, Object x, int... indexes) {
            if (offline) {
                if (x == null || !x.getClass().isArray()) {
                    out.append(name);
                    for (int i : indexes) {
                        out.printf("[%d]", i);
                    }
                    out.append("=").append("" + x);
                    out.println();
                } else {
                    indexes = Arrays.copyOf(indexes, indexes.length + 1);
                    if (x instanceof byte[]) {
                        byte[] arr = (byte[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof short[]) {
                        short[] arr = (short[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof boolean[]) {
                        boolean[] arr = (boolean[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof char[]) {
                        char[] arr = (char[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof int[]) {
                        int[] arr = (int[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof float[]) {
                        float[] arr = (float[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof double[]) {
                        double[] arr = (double[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else if (x instanceof long[]) {
                        long[] arr = (long[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    } else {
                        Object[] arr = (Object[]) x;
                        for (int i = 0; i < arr.length; i++) {
                            indexes[indexes.length - 1] = i;
                            debug(name, arr[i], indexes);
                        }
                    }
                }
            }
            return this;
        }

    }
}

