#include "secret.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef vector<ii> vii;
typedef long double ld;
#define FOR(i, a, b) for(int i = a; i < b; i++)
#define ROF(i, a, b) for(int i = a; i >= b; i--)
#define ms memset
#define pb push_back
#define F first
#define S second
vi arr[4000][1000];
int n;
vi a(1000);
void build(int v, int l, int r){
if (l == r){
arr[v][l].pb(a[l]); return;
}
int m = (l+r)/2;
arr[v][m].pb(a[m]);
int cnt = 0;
ROF(i, m-1, l){
arr[v][m].pb(Secret(a[i], arr[v][m][cnt]));
cnt++;
}
arr[v][m+1].pb(a[m+1]);
cnt = 0;
FOR(i, m+2, r+1){
arr[v][m+1].pb(Secret(arr[v][m+1][cnt], a[i]));
cnt++;
}
build(2*v, l, m);
build(2*v+1, m+1, r);
}
void Init(int N, int A[]) {
n = N;
FOR(i, 0, n) a[i] = A[i];
build(1, 0, n-1);
}
int query(int v, int tl, int tr, int l, int r){
int tm = (tl + tr) / 2;
if (l > tm+1) return query(2*v+1, tm+1, tr, l, r);
if (r < tm) return query(2*v, tl, tm, l, r);
if (l == tm+1) return arr[v][l][r-l];
if (r == tm) return arr[v][r][r-l];
return Secret(arr[v][tm][tm-l], arr[v][tm+1][r-tm-1]);
}
int Query(int L, int R) {
return query(1, 0, n-1, L, R);
}
