// 00:19:18 #include #include #include #include #include using namespace std; using i64 = long long; using u64 = unsigned long long; #define rep(i,n) for(i64 i=0; i<(i64)(n); i++) #define repr(i,n) for(i64 i=(i64)(n)-1; i>=0; i--) int main(){ i64 N, K; cin >> N >> K; vector A(N); rep(i,N) cin >> A[i]; vector XOR(N+1); rep(i,N) XOR[i+1] = XOR[i] ^ A[i]; i64 l = 0, r = N; rep(i,N+1) rep(j,i) if(XOR[i] == XOR[j]){ l = max(l, j); r = min(r, i); } vector C(2001001); bool ok = false; for(i64 i=0; i<=l; i++) for(i64 j=l+1; j<=N; j++) C[XOR[i]^XOR[j]]++; for(i64 p=l; p