#include <bits/stdc++.h>

using namespace std;
int v[100000];
bool coPrime(int a, int b)
{
    int rest;
    while(b)
    {
        rest = a % b;
        a = b;
        b = rest;
    }
    if(a==1)
        return 1;
    else
        return 0;

}
int main()
{
    int n, curr=0, ant=0, maxim, suma;

    cin >> n;

    for(int i=0; i<n; i++)
        cin >> v[i];

    sort(v, v+n);
    for(int i=0; i<n; i++)
    {
        if(i==0)
        {
            ant =v[0];
            continue;
        }
        else
        {
            curr = v[i];
            if(coPrime(ant, curr)==1)
            {
                suma = ant + curr;
                maxim = max(suma, maxim);
            }
            ant = curr;

        }
    }
    cout << maxim;
    return 0;
}