#include "prize.h"
#include <bits/stdc++.h>
#define X first
#define Y second
using namespace std;
typedef long long llint;
const int maxn = 2e5+10;
int l[maxn], r[maxn];
int out = -1;
int maxi = 0;
pair<int,int> query(int x) {
if (l[x] != -1) return {l[x], r[x]};
vector< int > v = ask(x);
l[x] = v[0], r[x] = v[1];
return {l[x], r[x]};
}
llint ra() {
return (llint)rand() + rand() + rand();
}
void solve(int l, int r) {
if (l > r) return;
if (out != -1) return;
if (query(l).X + query(l).Y == 0) {
out = l;
return;
}
if (query(l).X + query(l).Y < maxi) {solve(l + 1, r); return;}
if (l == r) return;
if (query(r).X + query(r).Y == 0) {
out = r;
return;
}
if (query(r).X + query(r).Y < maxi) {solve(l, r - 1); return;}
if (query(l).X == query(r).X) return;
int mid = (l + r) / 2;
solve(l, mid);
solve(mid, r);
}
int find_best(int n) {
memset(l, -1, sizeof l);
srand(13);
for (int i = 0; i < 200; i++) {
int x = ra() % min(1500, n);
pair<int, int> tr = query(x);
if (tr.X + tr.Y == 0) return x;
maxi = max(maxi, tr.X + tr.Y);
}
solve(0, n - 1);
assert(out != -1);
return out;
}
