#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 Int = long long; template ostream &operator<<(ostream &os, const pair &a) { return os << "(" << a.first << ", " << a.second << ")"; }; template ostream &operator<<(ostream &os, const vector &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; } template void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; } template bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; } template bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; } #define COLOR(s) ("\x1b[" s "m") constexpr int E = 20; int N, K; vector A; bool solve() { vector ASum(N + 1, 0); for (int i = 0; i < N; ++i) { ASum[i + 1] = ASum[i] ^ A[i]; } int l = 0, r = N; vector app(1 << E, -1); for (int j = 0; j <= N; ++j) { int &i = app[ASum[j]]; if (~i) { chmax(l, i); chmin(r, j); } i = j; } cerr<<"l = "<