// ~ Be Name Khoda ~ //
#include "prize.h"
#include <bits/stdc++.h>
//#pragma GCC optimize ("O3")
//#pragma GCC target("avx2")
//#pragma GCC optimize("unroll-loops,Ofast")
using namespace std;
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
typedef long long ll;
#define pb push_back
#define mp make_pair
#define all(x) x.begin(), x.end()
#define fi first
#define se second
const int maxn = 1e6 + 10;
const int maxn5 = 5e5 + 10;
const int maxnt = 1.2e6 + 10;
const int maxn3 = 1e3 + 10;
const int mod = 1e9 + 7;
const ll inf = 1e18;
pair <int, int> ans[maxn5];
map <int, int> av;
bool mark[maxn5];
int mx = 0, done = 0, dim = -1, cnt = 0, per[maxn5];
pair <int, int> assk(int id){
if(cnt > 10000)
exit(0);
if(!mark[id]){
vector <int> x = ask(id);
cnt++;
mark[id] = true;
ans[id].fi = x[0];
ans[id].se = x[1];
}
mx = max(mx, ans[id].fi + ans[id].se);
if(ans[id].fi + ans[id].se == 0)
dim = id;
return ans[id];
}
/*
int check(int l, int r){
l = lower_bound(all(good), l) - good.begin();
r = lower_bound(all(good), r) - good.begin();
return r - l;
}
*/
void solve(int l, int r){
if(dim != -1 || r <= l)
return;
int ptl = l, ptr = r - 1;
av.clear();
int lq = -1, rq = -1;
while(ptl < ptr && dim == -1){
assk(ptl);
assk(ptr);
av[ans[ptl].fi + ans[ptl].se] = ptl;
if(av.find(ans[ptr].fi + ans[ptr].se) != av.end()){
lq = av[ans[ptr].fi + ans[ptr].se];
rq = ptr;
break;
}
ptl++;
ptr--;
}
if(lq == -1)
return;
if(ans[rq].fi - ans[lq].fi){
int mid = (lq + rq) >> 1;
if(rng() % 2){
solve(lq + 1, mid);
solve(mid, rq);
}
else{
solve(mid, rq);
solve(lq + 1, mid);
}
}
return;
}
int find_best(int n){
//*
//*/
//mx = 1;
solve(0, n);
//assert(dim != -1);
//cout << cnt << endl;
return dim;
}
