#pragma GCC optimize ("O2") #pragma GCC target ("avx2") #include using namespace std; typedef long long ll; #define rep(i, n) for(int i = 0; i < (n); i++) #define rep1(i, n) for(int i = 1; i <= (n); i++) #define co(x) cout << (x) << "\n" #define cosp(x) cout << (x) << " " #define ce(x) cerr << (x) << "\n" #define cesp(x) cerr << (x) << " " #define pb push_back #define mp make_pair #define chmin(x, y) x = min(x, y) #define chmax(x, y) x = max(x, y) #define Would #define you #define please int main() { cin.tie(0); ios::sync_with_stdio(false); string S; cin >> S; if (S == "1") { co(-1); return 0; } if (S == "4") { co(-1); return 0; } while (S.size() >= 3) { S.erase(0, 1); } int s = stoi(S); if (s % 2) co(1); else if (s % 4 == 0) co(1); else co(-1); Would you please return 0; }