#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
#include<string>
#include<set>
#include<map>
#include<queue>
#include<algorithm>
using namespace std;
typedef long long ll;
const int maxn=100010;
const int inf =0x3f3f3f3f;
int n,m,k;
ll t;
int x,y;
int a[maxn];
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;++i)
	{
		scanf("%d",&a[i]);
	}
	sort(a+1,a+1+n);
	ll ans=a[n];
	for(int i=1;i<=n;++i)
	{
		t=0;
		for(int j=n;j>=i+1;--j)
		{
			if(a[j]%a[i]!=0)
			{
				t=a[i]+a[j];
				break;
			}
		}
		ans=max(ans,t);
	}
	printf("%lld\n",ans);
}