#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using P = pair; constexpr int INF = 1001001001; constexpr int mod = 1000000007; // constexpr int mod = 998244353; template inline bool chmax(T& x, T y){ if(x < y){ x = y; return true; } return false; } template inline bool chmin(T& x, T y){ if(x > y){ x = y; return true; } return false; } int main(){ ios::sync_with_stdio(false); cin.tie(nullptr); int N; cin >> N; vector a(N); for(int i = 0; i < N; ++i) cin >> a[i]; ll maxval = -1e+17, minval = 1e+17; auto dfs = [&](auto&& self, ll S, int i = 1) -> void { if(i == N / 2){ chmax(maxval, S); chmin(minval, S); return; } if(a[i] == 0){ self(self, S, i + 1); self(self, 0, i + 1); } else{ self(self, S + a[i], i + 1); self(self, S - a[i], i + 1); self(self, S * a[i], i + 1); self(self, S / a[i], i + 1); } }; dfs(dfs, a[0]); ll ans = -1e+17; auto dfs2 = [&](auto&& self, ll S, int i) -> void { if(i == N){ chmax(ans, S); return; } if(a[i] == 0){ self(self, S, i + 1); self(self, 0, i + 1); } else{ self(self, S + a[i], i + 1); self(self, S - a[i], i + 1); self(self, S * a[i], i + 1); self(self, S / a[i], i + 1); } }; dfs2(dfs2, maxval, N / 2); dfs2(dfs2, minval, N / 2); cout << ans << endl; return 0; }