#include <bits/stdc++.h>
#include "secret.h"
#define endl '\n'
#define fi first
#define se second
#define eb emplace_back
#define pb push_back
#define ce cout << endl
#define ALL(A) A.begin(), A.end()
#define FOR(i, l, r) for (int i = l; i <= r; i++)
#define FOR2(i, l, r) for (int i = l; i >= r; i--)
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
using pii = pair<int, int>;
using str = string;
using ull = unsigned long long;
using ld = long double;
const int INF = 1e9;
const int MAXN = 1000;
const int LOGN = 11;
const int heavy = 500;
const int MOD = 1e9 + 7;
int dx[] = {0, 1, 0, -1}; // east, south, west, north
int dy[] = {1, 0, -1, 0};
// T_Danh - Tri An High School
int X[MAXN];
int dat[LOGN][MAXN];
int mask[MAXN];
void divi(int l, int r, int lev) {
if (l == r) return;
int m = (l + r) >> 1;
dat[lev][m] = X[m];
FOR2(i,m - 1 , l) {
dat[lev][i] = Secret(X[i], dat[lev][i + 1]);
}
dat[lev][m + 1] = X[m + 1];
FOR(i,m + 2 , r) {
dat[lev][i] = Secret(dat[lev][i - 1], X[i]);
}
FOR(i,m + 1 , r) mask[i] ^= (1 << lev);
divi(l, m, lev + 1);
divi(m + 1, r, lev + 1);
}
void Init(int N, int A[]) {
FOR(i,0,N -1) X[i] = A[i];
divi(0, N - 1, 0);
}
int Query(int L, int R) {
if (L == R) return X[L];
int lev = __builtin_ctz(mask[L] ^ mask[R]);
return Secret(dat[lev][L], dat[lev][R]);
}
// int main() {
// ios::sync_with_stdio(0);
// cin.tie(0); cout.tie(0);
// int t = 1;
// while (t--) solve();
// return 0;
// }
