#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int gcd(int a, int b){
    if(a > b) return gcd(b, a);
    while(b%a != 0){
        int temp = b%a;
        b = a;
        a = temp;
    }
    return a;
}

int main() {
    int n; cin >> n;
    int arr[n];
    for(int i = 0;i < n;i++) cin >> arr[i];
    int ans = 0;
    for(int i = 0;i < n; i++){
        for(int j = i; j < n; j++){
            int m = arr[i];
            int sum = arr[i];
            int g = arr[i];
            for(int k = i + 1; k <=j ;k++){
                if(m < arr[k]) m = arr[i];
                sum += arr[k];
                g = gcd(arr[k], g);
            }
            ans = max(ans, (g*(sum - m)));
        }
    }
    cout << ans/2 << endl;
    return 0;
}