#include <bits/stdc++.h>
using namespace std;
long int hcf(int l, int r)
{
    int num1 = l;
    int num2 = r;
    if(num2!=0) 
    {
        return hcf(num2, num1%num2);
    }
    else 
    {
        return num1;
    }
}
long sum(int l, int r)
{
    int num1 = l;
    int num2 = r;
    return num1+num2; 
}
int main()
{
    int n, i, j, Sum=INT_MIN;
    cin>>n; 
    int a[n];
    for(i=0; i<n; i++)
    {
        cin>>a[i];
    }
    for(i=0; i<n; i++)
    {
        int l = a[i];
        for(j=i+1; j<n; j++)
        {
            int r = a[j];
            if(hcf(l, r)*(sum(l, r)-max(l, r))>Sum) 
            {
                Sum = hcf(l, r)*(sum(l, r)-max(l, r));
            }
        }
    }
    cout<<Sum<<endl;
    return 0; 
}