#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>
using namespace std;

#include <atcoder/all>
using namespace atcoder;

using mint = modint998244353;
using vm = vector<mint>;
using vvm = vector<vm>;
inline ostream &operator<<(ostream &os, const mint x)
{
    return os << x.val();
};
inline istream &operator>>(istream &is, mint &x)
{
    long long v;
    is >> v;
    x = v;
    return is;
};

struct Fast
{
    Fast()
    {
        std::cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << setprecision(10);
    }
} fast;

#define all(a) (a).begin(), (a).end()
#define contains(a, x) ((a).find(x) != (a).end())
#define rep(i, a, b) for (int i = (a); i < (int)(b); i++)
#define rrep(i, a, b) for (int i = (int)(b) - 1; i >= (a); i--)
#define YN(b) cout << ((b) ? "YES" : "NO") << "\n";
#define Yn(b) cout << ((b) ? "Yes" : "No") << "\n";
#define yn(b) cout << ((b) ? "yes" : "no") << "\n";

template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}

using ll = long long;
using vb = vector<bool>;
using vvb = vector<vb>;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;

template <typename T1, typename T2>
ostream &operator<<(ostream &os, pair<T1, T2> &p)
{
    os << "(" << p.first << "," << p.second << ")";
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, vector<T> &vec)
{
    for (int i = 0; i < (int)vec.size(); i++)
    {
        os << vec[i] << (i + 1 == (int)vec.size() ? "" : " ");
    }
    return os;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &vec)
{
    for (int i = 0; i < (int)vec.size(); i++)
        is >> vec[i];
    return is;
}

ll floor(ll a, ll b) { return a >= 0 ? a / b : (a + 1) / b - 1; }
ll ceil(ll a, ll b) { return a > 0 ? (a - 1) / b + 1 : a / b; }

void solve()
{
    int n;
    cin >> n;
    vi a(n);
    cin >> a;

    int m = 0;
    for (auto x : a)
        m += x;

    using bs = bitset<7500001>;
    bs bs1, bs2;
    bs1[0] = 1;

    rep(i, 0, n)
    {
        bs2 |= bs1 & (bs1 << a[i]);
        bs1 |= bs1 << a[i];
    }
    int ans = -1;
    for (int k = 1; m - 2 * k > 0; k++)
        if (bs2[k])
            ans = max(ans, m - 2 * k);
    cout << ans << "\n";
}

int main()
{
    int t = 1;
    // cin >> t;
    while (t--)
        solve();
}