#include #include #define rep(i,n) for(int i=0;i vi; typedef vector vl; typedef vector> vvi; typedef vector> vvl; typedef long double ld; typedef pair P; template ostream& operator<<(ostream& os, const static_modint& a) {os << a.val(); return os;} template ostream& operator<<(ostream& os, const dynamic_modint& a) {os << a.val(); return os;} template istream& operator>>(istream& is, static_modint& a) {long long x; is >> x; a = x; return is;} template istream& operator>>(istream& is, dynamic_modint& a) {long long x; is >> x; a = x; return is;} template istream& operator>>(istream& is, vector& v){int n = v.size(); assert(n > 0); rep(i, n) is >> v[i]; return is;} template ostream& operator<<(ostream& os, const pair& p){os << p.first << ' ' << p.second; return os;} template ostream& operator<<(ostream& os, const vector& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : " "); return os;} template ostream& operator<<(ostream& os, const vector>& v){int n = v.size(); rep(i, n) os << v[i] << (i == n - 1 ? "\n" : ""); return os;} template ostream& operator<<(ostream& os, const set& se){for(T x : se) os << x << " "; os << "\n"; return os;} template ostream& operator<<(ostream& os, const unordered_set& se){for(T x : se) os << x << " "; os << "\n"; return os;} template ostream& operator<<(ostream& os, const atcoder::segtree& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;} template ostream& operator<<(ostream& os, const atcoder::lazy_segtree& seg){int n = seg.max_right(0, [](S){return true;}); rep(i, n) os << seg.get(i) << (i == n - 1 ? "\n" : " "); return os;} template void chmin(T& a, T b){a = min(a, b);} template void chmax(T& a, T b){a = max(a, b);} // thanks for https://qiita.com/mdstoy/items/39104b686540c5f1dc6c template bool next_combination(const T first, const T last, int k) { const T subset = first + k; // empty container | k = 0 | k == n if (first == last || first == subset || last == subset) { return false; } T src = subset; while (first != src) { src--; if (*src < *(last - 1)) { T dest = subset; while (*src >= *dest) { dest++; } iter_swap(src, dest); rotate(src + 1, dest + 1, last); rotate(subset, subset + (last - dest) - 1, last); return true; } } // restore rotate(first, subset, last); return false; } const int INF = 1001001001; int main(){ int n; cin >> n; vector a(n); cin >> a; vector perm(n); rep(i, n) perm[i] = i; int m = n / 2; set set_sum; do{ int sum = 0; rep(i, m) sum += a[perm[i]]; if(set_sum.find(sum) == set_sum.end()) set_sum.insert(sum); else{ cout << "0\n"; return 0; } }while(next_combination(perm.begin(), perm.end(), m)); int prev = -INF; int ans = INF; for(int val : set_sum){ chmin(ans, val - prev); prev = val; } cout << ans << "\n"; return 0; }