#include "prize.h"
#include <iostream>
#define ll long long
using namespace std;
ll f = -1;
vector <int> R;
void solve(ll l, ll r, ll ql, ll qr) {
if (l > r || ql + qr == R[0] + R[1]) return;
ll mid = (l+r)/2;
for (int i=mid; i<=r; ++i) {
auto u = ask(i);
if (!u[0] && !u[1]) {
f = i;
return;
}
else if (u[0]+u[1] == R[0]+R[1]) {
solve(l, mid-1, ql, u[1]+(i-mid));
if (f != -1) return;
solve(i+1, r, u[0], qr);
return;
}
}
solve(l, mid-1, ql, qr+(r-mid+1));
}
void get(ll l, ll r) {
if (l == r) {
R = ask(l);
return;
}
ll mid = (l+r+1)/2;
auto u = ask(mid);
if (u[0] != mid) get(l, mid-1);
else get(mid, r);
}
int find_best(int n) {
solve(0, n-1, 0, 0);
return f;
}
