import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
import java.util.function.LongBinaryOperator;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.BufferedOutputStream;
import java.io.UncheckedIOException;
import java.nio.charset.Charset;
import java.util.StringTokenizer;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.io.BufferedReader;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 *
 * @author mikit
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        LightScanner in = new LightScanner(inputStream);
        LightWriter out = new LightWriter(outputStream);
        V solver = new V();
        solver.solve(1, in, out);
        out.close();
    }

    static class V {
        public void solve(int testNumber, LightScanner in, LightWriter out) {
            int n = in.ints();
            IntSparseTable st = new IntSparseTable(in.longs(n), IntMath::gcd);
            long ans = Math.max(st.query(1, n), st.query(0, n - 1));
            for (int i = 1; i < n - 1; i++) ans = Math.max(ans, IntMath.gcd(st.query(0, i), st.query(i + 1, n)));
            out.ans(ans).ln();
        }

    }

    static class LightWriter implements AutoCloseable {
        private final Writer out;
        private boolean autoflush = false;
        private boolean breaked = true;

        public LightWriter(Writer out) {
            this.out = out;
        }

        public LightWriter(OutputStream out) {
            this(new OutputStreamWriter(new BufferedOutputStream(out), Charset.defaultCharset()));
        }

        public LightWriter print(char c) {
            try {
                out.write(c);
                breaked = false;
            } catch (IOException ex) {
                throw new UncheckedIOException(ex);
            }
            return this;
        }

        public LightWriter print(String s) {
            try {
                out.write(s, 0, s.length());
                breaked = false;
            } catch (IOException ex) {
                throw new UncheckedIOException(ex);
            }
            return this;
        }

        public LightWriter ans(String s) {
            if (!breaked) {
                print(' ');
            }
            return print(s);
        }

        public LightWriter ans(long l) {
            return ans(Long.toString(l));
        }

        public LightWriter ln() {
            print(System.lineSeparator());
            breaked = true;
            if (autoflush) {
                try {
                    out.flush();
                } catch (IOException ex) {
                    throw new UncheckedIOException(ex);
                }
            }
            return this;
        }

        public void close() {
            try {
                out.close();
            } catch (IOException ex) {
                throw new UncheckedIOException(ex);
            }
        }

    }

    static final class BitMath {
        private BitMath() {
        }

        public static int count(int v) {
            v = (v & 0x55555555) + ((v >> 1) & 0x55555555);
            v = (v & 0x33333333) + ((v >> 2) & 0x33333333);
            v = (v & 0x0f0f0f0f) + ((v >> 4) & 0x0f0f0f0f);
            v = (v & 0x00ff00ff) + ((v >> 8) & 0x00ff00ff);
            v = (v & 0x0000ffff) + ((v >> 16) & 0x0000ffff);
            return v;
        }

        public static int msb(int v) {
            if (v == 0) {
                throw new IllegalArgumentException("Bit not found");
            }
            v |= (v >> 1);
            v |= (v >> 2);
            v |= (v >> 4);
            v |= (v >> 8);
            v |= (v >> 16);
            return count(v) - 1;
        }

    }

    static final class IntMath {
        private IntMath() {
        }

        public static long gcd(long a, long b) {
            long t;
            if (a == 0) return b;
            if (b == 0) return a;
            while (a % b > 0) {
                t = b;
                b = a % b;
                a = t;
            }
            return b;
        }

    }

    static class LightScanner {
        private BufferedReader reader = null;
        private StringTokenizer tokenizer = null;

        public LightScanner(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
        }

        public String string() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new UncheckedIOException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public int ints() {
            return Integer.parseInt(string());
        }

        public long longs() {
            return Long.parseLong(string());
        }

        public long[] longs(int length) {
            return IntStream.range(0, length).mapToLong(x -> longs()).toArray();
        }

    }

    static class IntSparseTable {
        private final int n;
        private final LongBinaryOperator f;
        private final long[][] table;

        public IntSparseTable(long[] a, LongBinaryOperator f) {
            this.n = a.length;
            this.f = f;
            this.table = new long[30][];
            table[0] = a.clone();
            for (int i = 1; (1 << i) < n; i++) {
                table[i] = new long[n];
                int r = 1 << i, d = r + r;
                for (int j = r - 1; j < n; j += d) {
                    table[i][j] = a[j];
                    for (int k = 1; k < r; k++)
                        table[i][j - k] = f.applyAsLong(a[j - k], table[i][j - k + 1]);
                }
                for (int j = r; j < n; j += d) {
                    table[i][j] = a[j];
                    for (int k = j + 1; k < j + r && k < n; k++)
                        table[i][k] = f.applyAsLong(a[k], table[i][k - 1]);
                }
            }
        }

        public long query(int l, int r) {
            if (r <= l || l < 0 || n < r) throw new RuntimeException();
            if (l == --r) return table[0][l];
            int k = BitMath.msb(l ^ r);
            return f.applyAsLong(table[k][l], table[k][r]);
        }

    }
}



Measured memory_bytes: 56508