// inputに入力データ全体が入る
function Main(input) {
    // 1行目がinput[0], 2行目がinput[1], …に入る
    input = input.split("\n");
    // 数値の配列を作る
    const numList0 = input[0].split(' ').map(x => parseInt(x, 10));
    const N = numList0[0];
    const aList = input[1].split(' ').map(x => parseInt(x, 10));

    const gcd = function(a, b) {
        if ( ! b) {
            return a;
        }
    
        return gcd(b, a % b);
    };

    const lList = [0];
    const rList = [0];
    var newL = 0;
    var newR = 0;
    for (var i = 0; i < N; i++) {
        newL = gcd(newL, aList[i]);
        lList.push(newL);
        newR = gcd(newR, aList[N - i - 1]);
        rList.unshift(newR);
    }

    var max = 0;
    for (var i = 0; i < N; i++) {
        var result = gcd(lList[i], rList[i + 1]);
        max = Math.max(max, result);
    }

    console.log(max);
}

Main(require("fs").readFileSync("/dev/stdin", "utf8"));