#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int num = 0;
#define sz(a) (int)(a.size());
vector<int>res[200000];
int cnt = 0;
vector<int> askk(int v){
cnt++;
assert(cnt<=9999);
return ask(v);
}
int solve(int l,int r,int lf = 0,int rg = 0){
cerr<<l<<" "<<r<<'\n';
if(l > r)return -1;
int mid = (l+r)/2;
int il = mid;
int ir = mid;
int cur = mid;
for(int i=0;i<=r-l+1;i++){
if(cur < l || cur > r)break;
res[cur] = askk(cur);
if(!res[cur][0] && !res[cur][1])return cur;
else if(res[cur][0]+res[cur][1] == num)break;
if(i%2 == 0){
ir++;
cur = ir;
}else{
il--;
cur = il;
}
}
cerr<<cur<<'\n';
if(cur < l || cur > r)return -1;
if(il-1 >= l && res[il][0]-lf > 0){
int c = solve(l,il-1,lf,res[il][1]);
if(c!=-1)return c;
}
if(ir+1<=r && res[ir][1] - rg > 0){
int c = solve(ir+1,r,res[ir][0],rg);
if(c!=-1)return c;
}
return -1;
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int find_best(int n) {
if(n<=5000){
for(int i=0;i<n;i++){
vector<int>res = ask(i);
if(res[0] == 0 && res[1] == 0)return i;
}
}
int p = 0;
for(int i=0;i<min(n,(int)(sqrt(n)+30)) && num < 22;i++){
vector<int>res = ask(i);
if(!res[0] && !res[1])return i;
if(res[0] + res[1] > num){
num = res[0] + res[1];
p = i;
}
}
//d&c to try all small guys since < #small guys < sqrt(n)
return solve(p,n-1,p,0);
}
