import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;

public class Main {

    public static void main(String[] args) {
	InputStream inputStream = System.in;
	OutputStream outputStream = System.out;
	MyInput in = new MyInput(inputStream);
	PrintWriter out = new PrintWriter(outputStream);
	TaskX solver = new TaskX();
	solver.solve(1, in, out);
	out.close();
    }

    static int INF = 1 << 30;
    static long LINF = 1L << 55;
    static int MOD = 1000000007;
    static int[] mh4 = { 0, -1, 1, 0 };
    static int[] mw4 = { -1, 0, 0, 1 };
    static int[] mh8 = { -1, -1, -1, 0, 0, 1, 1, 1 };
    static int[] mw8 = { -1, 0, 1, -1, 1, -1, 0, 1 };

    static class TaskX {

	public void solve(int testNumber, MyInput in, PrintWriter out) {

	    int N = in.nextInt();
	    long[] A = in.nextLongArray(N);

	    GMQ gmq = new GMQ(N, new P(0));
	    for (int i = 0; i < N; i++) {
		gmq.update(i, new P(A[i]));
	    }

	    long ans = 0;
	    for (int i = 0; i < N; i++) {
		gmq.update(i, new P(0));
		ans = Math.max(ans, gmq.query(0, N).get());
		gmq.update(i, new P(A[i]));
	    }

	    out.println(ans);

	}

	class P {
	    long a;

	    public P(long a) {
		super();
		this.a = a;
	    }

	    @Override
	    public String toString() {
		return Long.toString(a);
	    }

	    public long get() {
		return this.a;
	    }

	}

	class GMQ extends AbstractSegmentTree<P> {
	    public GMQ(int size, P initial_value) {
		super(size, initial_value);
	    }

	    @Override
	    P merge(P x, P y) {
		return new P(gcd(x.a, y.a));
	    }
	}

	@SuppressWarnings("unchecked")
	abstract class AbstractSegmentTree<T> {
	    int size;
	    T[] dat;
	    T INITIAL_VALUE;

	    abstract T merge(T x, T y);

	    public AbstractSegmentTree(int n, T initial_value) {
		size = 1;
		this.INITIAL_VALUE = initial_value;
		while (size < n) {
		    size *= 2;
		}
		dat = (T[]) new Object[size * 2];
		for (int i = 0; i < size * 2; i++) {
		    dat[i] = INITIAL_VALUE;
		}
	    }

	    void update(int k, T a) {
		k += size;
		dat[k] = a;
		while (k > 0) {
		    k /= 2;
		    dat[k] = merge(dat[2 * k], dat[2 * k + 1]);
		}
	    }

	    private T query(int a, int b, int k, int l, int r) {
		if (r <= a || b <= l)
		    return INITIAL_VALUE;

		if (a <= l && r <= b) {
		    return dat[k];
		} else {
		    T vl = query(a, b, 2 * k, l, (l + r) / 2);
		    T vr = query(a, b, 2 * k + 1, (l + r) / 2, r);
		    return merge(vl, vr);
		}
	    }

	    T query(int a, int b) {
		return query(a, b, 1, 0, size);
	    }
	}
    }

    public static long gcd(long a, long b) {
	return (b == 0) ? a : gcd(b, a % b);
    }

    static class MyInput {
	private final BufferedReader in;
	private static int pos;
	private static int readLen;
	private static final char[] buffer = new char[1024 * 8];
	private static char[] str = new char[500 * 8 * 2];
	private static boolean[] isDigit = new boolean[256];
	private static boolean[] isSpace = new boolean[256];
	private static boolean[] isLineSep = new boolean[256];

	static {
	    for (int i = 0; i < 10; i++) {
		isDigit['0' + i] = true;
	    }
	    isDigit['-'] = true;
	    isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true;
	    isLineSep['\r'] = isLineSep['\n'] = true;
	}

	public MyInput(InputStream is) {
	    in = new BufferedReader(new InputStreamReader(is));
	}

	public int read() {
	    if (pos >= readLen) {
		pos = 0;
		try {
		    readLen = in.read(buffer);
		} catch (IOException e) {
		    throw new RuntimeException();
		}
		if (readLen <= 0) {
		    throw new MyInput.EndOfFileRuntimeException();
		}
	    }
	    return buffer[pos++];
	}

	public int nextInt() {
	    int len = 0;
	    str[len++] = nextChar();
	    len = reads(len, isSpace);
	    int i = 0;
	    int ret = 0;
	    if (str[0] == '-') {
		i = 1;
	    }
	    for (; i < len; i++)
		ret = ret * 10 + str[i] - '0';
	    if (str[0] == '-') {
		ret = -ret;
	    }
	    return ret;
	}

	public long nextLong() {
	    int len = 0;
	    str[len++] = nextChar();
	    len = reads(len, isSpace);
	    int i = 0;
	    long ret = 0;
	    if (str[0] == '-') {
		i = 1;
	    }
	    for (; i < len; i++)
		ret = ret * 10 + str[i] - '0';
	    if (str[0] == '-') {
		ret = -ret;
	    }
	    return ret;
	}

	public char nextChar() {
	    while (true) {
		final int c = read();
		if (!isSpace[c]) {
		    return (char) c;
		}
	    }
	}

	public String nextString() {
	    return new String(nextChars());
	}

	public char[] nextChars() {
	    int len = 0;
	    str[len++] = nextChar();
	    len = reads(len, isSpace);
	    return Arrays.copyOf(str, len);
	}

	public char[][] next2DChars(int h, int w) {
	    char[][] s = new char[h][w];
	    for (int i = 0; i < h; i++) {
		s[i] = nextChars();
	    }
	    return s;
	}

	int reads(int len, boolean[] accept) {
	    try {
		while (true) {
		    final int c = read();
		    if (accept[c]) {
			break;
		    }
		    if (str.length == len) {
			char[] rep = new char[str.length * 3 / 2];
			System.arraycopy(str, 0, rep, 0, str.length);
			str = rep;
		    }
		    str[len++] = (char) c;
		}
	    } catch (MyInput.EndOfFileRuntimeException e) {
	    }
	    return len;
	}

	public int[] nextIntArray(final int n) {
	    final int[] res = new int[n];
	    for (int i = 0; i < n; i++) {
		res[i] = nextInt();
	    }
	    return res;
	}

	public int[] nextIntArray1Index(final int n) {
	    final int[] res = new int[n + 1];
	    for (int i = 1; i < n + 1; i++) {
		res[i] = nextInt();
	    }
	    return res;
	}

	public int[] nextIntArrayDec(final int n) {
	    final int[] res = new int[n];
	    for (int i = 0; i < n; i++) {
		res[i] = nextInt() - 1;
	    }
	    return res;
	}

	public long[] nextLongArray(final int n) {
	    final long[] res = new long[n];
	    for (int i = 0; i < n; i++) {
		res[i] = nextLong();
	    }
	    return res;
	}

	public long[] nextLongArray1Index(final int n) {
	    final long[] res = new long[n + 1];
	    for (int i = 1; i < n + 1; i++) {
		res[i] = nextLong();
	    }
	    return res;
	}

	public long[] nextLongArrayDec(final int n) {
	    final long[] res = new long[n];
	    for (int i = 0; i < n; i++) {
		res[i] = nextLong() - 1;
	    }
	    return res;
	}

	public double nextDouble() {
	    return Double.parseDouble(nextString());
	}

	public double[] nextDoubleArray(int n) {
	    double[] res = new double[n];
	    for (int i = 0; i < n; i++) {
		res[i] = nextDouble();
	    }
	    return res;
	}

	static class EndOfFileRuntimeException extends RuntimeException {
	}

    }

}


Measured memory_bytes: 102472