#[allow(unused_imports)]
use std::cmp::{max, min};
#[allow(unused_imports)]
use std::collections::{BTreeMap, BTreeSet, BinaryHeap, HashMap, HashSet, VecDeque};
#[allow(unused_imports)]
use std::fs::File;
#[allow(unused_imports)]
use std::io::prelude::*;
#[allow(unused_imports)]
use std::io::{stdin, stdout, BufReader, BufWriter, Stdin, Stdout, Write};
#[allow(unused_imports)]
use std::mem::swap;
#[allow(unused_imports)]
use std::str::FromStr;

type BoxResult<T> = Result<T, Box<std::error::Error>>;

fn main() {
    let mut scanner = Scanner::new(stdin());
    let n = scanner.read::<usize>().unwrap();
    let arr = scanner.read_vector::<usize>().unwrap();
    let segtree = SegmentTree::new(&arr);
    let mut maximum = 1;
    for i in 0..n {
        if i == 0 {
            maximum = max(segtree.query(1, n - 1), maximum);
        } else if i == n - 1 {
            maximum = max(segtree.query(0, n - 2), maximum);
        } else {
            let left = segtree.query(0, i - 1);
            let right = segtree.query(i + 1, n - 1);
            maximum = max(gcd(left, right), maximum);
        }
    }
    println!("{}", maximum);
}

struct SegmentTree {
    size: usize,
    values: Vec<usize>,
}

impl SegmentTree {
    fn new(arr: &[usize]) -> SegmentTree {
        let len = arr.len();
        let mut size = 1;
        while size < len {
            size *= 2;
        }
        let mut values = vec![1; 2 * size - 1];
        for i in (0..values.len()).rev() {
            if i >= size - 1 && i + 1 - size < len {
                values[i] = arr[i + 1 - size];
            } else if i < size - 1 {
                values[i] = gcd(values[2 * i + 1], values[2 * i + 2]);
            }
        }
        SegmentTree{ size: size, values: values }
    }
    fn query_rec(&self, start: usize, end: usize, index: usize, left: usize, right: usize) -> usize {
        if start == left && end == right {
            return self.values[index];
        }
        let mid = (left + right) / 2;
        if end <= mid {
            return self.query_rec(start, end, 2 * index + 1, left, mid);
        } else if start > mid {
            return self.query_rec(start, end, 2 * index + 2, mid + 1, right);
        } else {
            let left_gcd = self.query_rec(start, mid, 2 * index + 1, left, mid);
            let right_gcd = self.query_rec(mid + 1, end, 2 * index + 2, mid + 1, right);
            return gcd(left_gcd, right_gcd);
        }
    }
    fn query(&self, start: usize, end: usize) -> usize {
        self.query_rec(start, end, 0, 0, self.size - 1)
    }
}

fn gcd(x: usize, y: usize) -> usize {
    let mut x = x;
    let mut y = y;
    if x < y {
        swap(&mut x, &mut y);
    }
    
    loop {
        let residual = x % y;
        if residual == 0 {
            break;
        }
        x = y;
        y = residual;
    }

    y
}

#[allow(dead_code)]
struct Scanner<R> {
    reader: BufReader<R>,
    buffer: String,
}

impl<R> Scanner<R>
where
    R: Read,
{
    #[allow(dead_code)]
    fn new(inner: R) -> Scanner<R> {
        let reader = BufReader::new(inner);
        let buffer = String::new();
        Scanner {
            reader: reader,
            buffer: buffer,
        }
    }

    #[allow(dead_code)]
    fn with_capacity(capacity: usize, inner: R) -> Scanner<R> {
        let reader = BufReader::with_capacity(capacity, inner);
        let buffer = String::new();
        Scanner {
            reader: reader,
            buffer: buffer,
        }
    }

    #[allow(dead_code)]
    fn read<T>(&mut self) -> BoxResult<T>
    where
        T: FromStr,
        T::Err: std::fmt::Debug,
        T::Err: std::error::Error,
        T::Err: 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let parsed = self.buffer.trim().parse()?;
        self.buffer.clear();
        Ok(parsed)
    }

    #[allow(dead_code)]
    fn read_vector<T>(&mut self) -> BoxResult<Vec<T>>
    where
        T: FromStr,
        T::Err: std::fmt::Debug,
        T::Err: std::error::Error,
        T::Err: 'static,
    {
        self.reader.read_line(&mut self.buffer)?;
        let parsed_vec = self
            .buffer
            .trim()
            .split_whitespace()
            .map(|s| s.parse())
            .collect::<Result<Vec<_>, _>>()?;
        self.buffer.clear();
        Ok(parsed_vec)
    }

    #[allow(dead_code)]
    fn read_matrix<T>(&mut self, lines: usize) -> BoxResult<Vec<Vec<T>>>
    where
        T: FromStr,
        T::Err: std::fmt::Debug,
        T::Err: std::error::Error,
        T::Err: 'static,
    {
        let mut parsed_matrix = vec![];
        for _ in 0..lines {
            self.reader.read_line(&mut self.buffer)?;
            parsed_matrix.push(
                self.buffer
                    .trim()
                    .split_whitespace()
                    .map(|s| s.parse())
                    .collect::<Result<Vec<_>, _>>()?,
            );
            self.buffer.clear();
        }
        Ok(parsed_matrix)
    }

    #[allow(dead_code)]
    fn read_chars(&mut self) -> BoxResult<Vec<char>> {
        self.reader.read_line(&mut self.buffer)?;
        let chars = self.buffer.trim().chars().collect::<Vec<_>>();
        self.buffer.clear();
        Ok(chars)
    }
}


Measured memory_bytes: 10492