#include "prize.h"
#include <bits/stdc++.h>
#define pii pair<int,int>
using namespace std;
vector <int> v;
int go (int l, int r, pii left, pii right) {
if (l > r) {
return -1;
}
int mid = (l + r) >> 1;
v = ask(mid);
pii c = {v[0], v[1]};
if (v[0] == 0 && v[1] == 0) {
return mid;
}
if (l == r) {
return -1;
}
int ret = -1;
if (c.second > 0 && c != right) {
ret = go(mid + 1, r, c, right);
}
if (ret == -1 && c.first > 0 && c != left) {
ret = go(l, mid - 1, left, c);
}
return ret;
}
int find_best(int n) {
return go(0, n - 1, {-1, -1}, {-1, -1});
}
