#include <algorithm>
#include <cassert>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <iostream>
#include <tuple>
#include <vector>
#include <map>
#include <set>
#include <queue>
#include <ranges>
#include <iomanip>
using namespace std;
using ll = long long;

auto range(int n) { return views::iota(0, n); }

template<class T, class U> ostream& operator<<(ostream& os, const pair<T, U>& p){ return os << "{" << p.first << ", " << p.second << "}"; }
template<typename T> ostream& operator<<(ostream& os, const vector<T>& obj) { os << "{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T> ostream& operator<<(ostream& os, const set<T>& obj) { os << "set{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }
template<typename T, typename U> ostream& operator<<(ostream& os, const map<T, U>& obj) { os << "map{"; for (const auto& e : obj) os << e << ", "; return os << "}"; }

#ifdef ONLINE_JUDGE
#define dump(expr) ;
#else
#define dump(expr) { cerr << "\033[33m#L" << __LINE__ << ": " << expr << "\033[39m" << endl; }
#endif

int depthmax;
vector<int> vs;

bool good;
vector<int> ans;
void dfs(int j, int tot, char p) {
  if (j == depthmax) {
    // if (tot == 0 && p) good = true;
    return;
  }

  ans[j] = 0;
  dfs(j + 1, tot, p);
  if (good) return;

  ans[j] = vs[j];
  dfs(j + 1, tot + vs[j], 1);
  if (good) return;

  ans[j] = -vs[j];
  dfs(j + 1, tot - vs[j], 1);
  if (good) return;
}

void solve() {
  int n = 19;
  vs.resize(n);
//  for (int i : range(n)) cin >> vs[i];

  depthmax = min(n, 19);
  good = false;
  ans.resize(depthmax);
  dfs(0, 0, 0);
}

int main() {
  cout << fixed << setprecision(12);
  solve();
}