#include <bits/stdc++.h>
#include "prize.h"
using namespace std;
mt19937 rng((long long) (new char));
const int N = 200000 + 7;
vector<int> ret[N];
int sol;
vector<int> get(int pos) {
if (ret[pos].empty()) {
ret[pos] = ask(pos);
}
if (ret[pos][0] == 0 && ret[pos][1] == 0) {
sol = pos;
}
return ret[pos];
}
int rn(int l, int r) {
return l + rng() % (r - l + 1);
}
int rep(int l, int r) {
if (l > r) {
return 0;
}
int m = (l + r) / 2;
vector<int> v = get(m);
if (v[0] == 0 && v[1] == 0) {
return m;
}
if (v[0] == 0) {
return rep(m + 1, r);
}
if (v[1] == 0) {
return rep(l, m - 1);
}
if (v[0] > v[1]) {
int x = rep(l, m - 1);
if (x) {
return x;
} else {
return rep(m + 1, r);
}
} else {
int x = rep(m + 1, r);
if (x) {
return x;
} else {
return rep(l, m - 1);
}
}
}
int find_best(int n) {
sol = -1;
vector<int> bucket(n);
int r = 200;
for (int i = 0; i < n; i++) {
bucket[i] = i / r;
}
vector<pair<int, int>> buckets;
int l = 0;
while (l < n) {
int r = l;
while (r + 1 < n && bucket[l] == bucket[r + 1]) {
r++;
}
buckets.push_back({l, r});
l = r + 1;
}
shuffle(buckets.begin(), buckets.end(), rng);
for (auto &it : buckets) {
int l = it.first;
int r = it.second;
vector<int> vl = get(l);
vector<int> vr = get(r);
if (sol != -1) {
return sol;
}
if (vl != vr) {
int x = rep(l, r);
if (x) {
return x;
}
}
}
while (1) {
}
}
