#include <bits/stdc++.h>
using namespace std;
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
 
    int n;
    cin >> n;
    const int MAXA = 1e6;
    vector<int> cnt(MAXA+1, 0);
 
    for(int i = 0; i < n; i++){
        int x;
        cin >> x;
        cnt[x]++;
    }
 
    // duyệt từ giá trị lớn nhất xuống
    for(int g = MAXA; g >= 1; g--){
        int c = 0;
        for(int multiple = g; multiple <= MAXA; multiple += g){
            c += cnt[multiple];
        }
        if(c >= 2){
            cout << g;
            return 0;
        }
    }
 
    return 0;
}
 

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