#include <bits/stdc++.h>

#pragma GCC optimize("O3")
//#define int long long

using namespace std;

signed main(){
	cin.tie(0);
	ios::sync_with_stdio(0);
	int n; cin >> n;
	vector<int> a(n), cnt(21);
	vector<vector<int>> dp(1 << 20, vector<int>(20));
	int all = 0;
	for (int& v : a) {
		cin >> v, --v;
		cnt[v] += 1;
		all |= 1 << v;
	}
	for (int i = 0; i < 20; ++i) 
		dp[1 << i][i] = (cnt[i] - 1) * (i+1);
	for (int i  = 0; i < (1 << 20); ++i)
		if ((all | i) == all) {
			for (int k = 0; k < 20; ++k)
				if (!((1 << k) & i) && cnt[k]) {
					int ni = i | (1 << k);
					for (int j = 0; j < 20; ++j)
						if ((1 << j) & i) {
							dp[ni][k] = max(dp[ni][k], dp[i][j] + __gcd(j + 1, k + 1) + (cnt[k] - 1) * (k + 1));
						}
				}
		}
	int res = 0;
	for (int i = 0; i < 20; ++i)
		res = max(res, dp[all][i]);

	cout << res << '\n';
	
}