#include "secret.h"
#include <bits/stdc++.h>
using namespace std;
const int MX = 1005;
int N;
int A[MX];
int leftVal[20][MX], rightVal[20][MX];
// 每層分治的跨越值
void build(int l, int r, int d) {
if (l == r) return;
int mid = (l + r) / 2;
// 往左算
leftVal[d][mid] = A[mid];
for (int i = mid-1; i >= l; i--)
leftVal[d][i] = Secret(A[i], leftVal[d][i+1]);
// 往右算
rightVal[d][mid+1] = A[mid+1];
for (int i = mid+2; i <= r; i++)
rightVal[d][i] = Secret(rightVal[d][i-1], A[i]);
build(l, mid, d+1);
build(mid+1, r, d+1);
}
void Init(int n, int a[]) {
N = n;
for (int i = 0; i < N; i++) A[i] = a[i];
build(0, N-1, 0);
}
int query(int l, int r, int ql, int qr, int d) {
if (ql <= l && r <= qr) {
// fully inside
return -1; // 不直接回，因為要判斷跨不跨
}
int mid = (l + r) / 2;
if (qr <= mid) return query(l, mid, ql, qr, d+1);
if (ql > mid) return query(mid+1, r, ql, qr, d+1);
// 跨越區間
return Secret(leftVal[d][ql], rightVal[d][qr]);
}
int Query(int L, int R) {
return query(0, N-1, L, R, 0);
}
