import java.io.IOException
import java.io.InputStream
import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val n = sc.nextInt()
    val a = sc.nextIntArray(n)
    val l = IntArray(n)
    for (i in 0..n - 2) {
        l[i + 1] = gcd(l[i], a[i])
    }
    val r = IntArray(n)
    for (i in n - 1 downTo 1) {
        r[i - 1] = gcd(r[i], a[i])
    }
    val ans = (0 until n).map { gcd(l[it], r[it]) }.max()
    println(ans)
}

fun gcd(n: Int, m: Int): Int = if (m == 0) n else gcd(m, n % m)

class Scanner(private val `in`: InputStream) {
    private val buffer = ByteArray(1024)
    private var ptr = 0
    private var buflen = 0

    companion object {
        private fun isPrintableChar(b: Byte): Boolean = b in 33..126
        private fun isNumericChar(b: Byte): Boolean = b in 48..57
        private fun digit(b: Byte): Int = b - 48
    }

    fun hasNextByte(): Boolean {
        if (ptr < buflen) return true
        ptr = 0
        try {
            buflen = `in`.read(buffer)
        } catch (e: IOException) {
            e.printStackTrace()
        }
        return 0 < buflen
    }

    private fun readByte(): Byte = if (hasNextByte()) buffer[ptr++] else -1

    private fun skipUnprintable() {
        while (hasNextByte() && !isPrintableChar(buffer[ptr])) ptr++
    }

    fun hasNext(): Boolean {
        skipUnprintable()
        return hasNextByte()
    }

    fun next(): String {
        if (!hasNext()) throw NoSuchElementException()
        return buildString {
            var b = readByte()
            while (isPrintableChar(b)) {
                appendCodePoint(b.toInt())
                b = readByte()
            }
        }
    }

    fun nextInt(): Int {
        if (!hasNext()) throw NoSuchElementException()
        var n = 0
        var b = readByte()
        val minus = b.toChar() == '-'
        if (minus) b = readByte()
        if (!isNumericChar(b)) throw NumberFormatException()
        do {
            n *= 10
            n += digit(b)
            b = readByte()
        } while (isNumericChar(b))
        return if (minus) -n else n
    }

    fun nextInts(n: Int): Array<Int> = Array(n) { nextInt() }

    fun nextIntArray(n: Int): IntArray = IntArray(n) { nextInt() }

    fun nextIntArrays(n: Int, m: Int): Array<IntArray> {
        val arrays = Array(m) { IntArray(n) }
        repeat(n) { i -> repeat(m) { j -> arrays[j][i] = nextInt() } }
        return arrays
    }

    fun nextLong(): Long {
        if (!hasNext()) throw NoSuchElementException()
        var n = 0L
        var b = readByte()
        val minus = b.toChar() == '-'
        if (minus) b = readByte()
        if (!isNumericChar(b)) throw NumberFormatException()
        do {
            n *= 10
            n += digit(b)
            b = readByte()
        } while (isNumericChar(b))
        return if (minus) -n else n
    }

    fun nextLongs(n: Int): Array<Long> = Array(n) { nextLong() }

    fun nextLongArray(n: Int): LongArray = LongArray(n) { nextLong() }

    fun nextLongArrays(n: Int, m: Int): Array<LongArray> {
        val arrays = Array(m) { LongArray(n) }
        repeat(n) { i -> repeat(m) { j -> arrays[j][i] = nextLong() } }
        return arrays
    }

}

Measured memory_bytes: 36488