#ifdef NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(int i=0; i<int(n); i++)
const i64 INF = 1001001001001001001;
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
#include <atcoder/modint>
#include <bitset>
#include <type_traits>
namespace nachia{
template<class TargetInt, TargetInt Max, TargetInt Min = TargetInt(1), class Callback>
void CallWithConstexprFittingInt(TargetInt val, const Callback& callback){
    if(Max / 2 < val || Max / 2 < Min){ callback(std::integral_constant<TargetInt, Max>()); return; }
    CallWithConstexprFittingInt<TargetInt, Max / 2, Min, Callback>(val, callback);
}
}
using Modint = atcoder::static_modint<998244353>;
using namespace std;

void testcase(){
    int N; cin >> N;
    vector<int> A(N); rep(i,N) cin >> A[i];
    int Z = 0;
    for(auto a : A) Z += a;
    int ans = -1;
    nachia::CallWithConstexprFittingInt<int, 1<<23>(Z/2+1, [&](auto X){
        constexpr int x = X.value;
        using Set = bitset<x>;
        Set dp;
        Set res;
        dp.set(0);
        for(int a : A){
            Set nx = dp;
            nx <<= a;
            res |= nx & dp;
            dp |= nx;
        }
        for(int i=0; i<x; i++) if(res.test(i)){ ans = Z - i * 2; break; }
    });
    if(ans <= 0) ans = -1;
    cout << ans << '\n';
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    testcase();
    return 0;
}