#include "secret.h"
#include <bits/stdc++.h>
#define pii pair<int, int>
using namespace std;
const int MAX = 1004;
map<pii, int> D;
int N, S[MAX];
void DnC1(int L, int R) {
if (L >= R) return;
int mid = (L + R) >> 1;
int pv = -1;
for (int i = mid - 1; i >= L; --i) {
int n = -1;
if (pv == -1) n = Secret(S[i], S[mid]);
else n = Secret(S[i], pv);
pv = D[{i, mid}] = n;
}
pv = -1;
for (int i = mid + 2; i <= R; ++i) {
int n = -1;
if (pv == -1) n = Secret(S[mid + 1], S[i]);
else n = Secret(pv, S[i]);
pv = D[{mid + 1, i}] = n;
}
DnC1(L, mid);
DnC1(mid + 1, R);
}
void Init(int _N, int A[]) {
N = _N;
for (int i = 0; i < N; ++i) S[i] = A[i];
DnC1(0, N - 1);
for (int i = 0; i < N; ++i) D[{i, i}] = A[i];
}
int DnC2(int L, int R, int s, int e) {
if (L >= R) return -1;
int mid = (L + R) >> 1;
if (s <= mid && mid < e) {
int a = D[{s, mid}], b = D[{mid + 1, e}];
return Secret(a, b);
}
if (e <= mid) return DnC2(L, mid, s, e);
else return DnC2(mid + 1, R, s, e);
}
int Query(int L, int R) {
if (D.find(pii{L, R}) != D.end()) return D[{L, R}];
return DnC2(0, N - 1, L, R);
}
