#include "prize.h"
#include<bits/stdc++.h>
using namespace std;
#define in insert
#define all(x) x.begin(),x.end()
#define pb push_back
#define eb emplace_back
#define ff first
#define ss second
//#define int long long
typedef long long ll;
typedef vector<int> vi;
typedef set<int> si;
typedef multiset<int> msi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;
const int mxn = 2e5 + 10;
pair<int, int> did[mxn];
int mx, ans;
int get(int i) {
if(did[i].ff != -1) return did[i].ff + did[i].ss;
auto sus = ask(i);
did[i].ff = sus[0]; did[i].ss = sus[1];
return did[i].ff + did[i].ss;
}
void solve(int l, int r) {
if(l > r) return;
int m = (l + r) / 2;
if(get(m) == 0) ans = m;
if(l == r) return;
int m1 = m, m2 = m;
while(m1 >= l) {
if(get(m1) == mx) break;
if(get(m1) == 0) ans = m1;
m1--;
}
while(m2 <= r) {
if(get(m2) == mx) break;
if(get(m2) == 0) ans = m2;
m2++;
}
if(m1 >= l && did[l].ff < did[m1].ff) solve(l, m1);
if(r >= m2 && did[r].ff > did[m2].ff) solve(m2, r);
}
int find_best(int n) {
if(n == 1) return 0;
for(int i = 0; i < n; i++) {
did[i] = {-1, -1};
}
for(int i = 0; i < min(n, 469); i++) {
if(get(i) == 0) return i;
mx = max(mx, get(i));
}
solve(0, n - 1);
return ans;
}
