#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
vector<int> ans[210000];
int mx = -1, ll, rr, Q = -1;
int find(int l, int r){
if(Q != -1){
return 0;
}
if(ans[l][0] == ans[r][0]){
return 0;
}
if(ll > r || rr < l){
return 0;
}
int m = (l + r) >> 1, L = m, R = m + 1;
while(l < L){
if(L < ll){
break;
}
ans[L] =ask(L);
if(ans[L][0] + ans[L][1] == mx){
break;
}
if(ans[L][0] + ans[L][1] == 0){
Q = L;
return L;
}
if(ans[L][0] == 0){
ll = L + 1;
break;
}
L--;
}
while(r > R){
if(R > rr){
break;
}
ans[R] =ask(R);
if(ans[R][0] + ans[R][1] == mx){
break;
}
if(ans[R][0] + ans[R][1] == 0){
Q = R;
return R;
}
if(ans[R][1] == 0){
rr = R - 1;
break;
}
R++;
}
return max(find(l, L), find(R, r));
}
int find_best(int n) {
ll = 0;
rr = n - 1;
for(int i = 0; i < 448; i++){
ans[i] = ask(i);
if(ans[i][0] + ans[i][1] == 0){
return i;
}
mx = max(mx, ans[i][0] + ans[i][1]);
}
int l = 0, r = n - 1;
while(true){
if(ans[l][0] + ans[l][1] == mx){
break;
}
l++;
}
while(true){
ans[r] = ask(r);
if(ans[r][0] + ans[r][1] == mx){
break;
}
if(ans[r][0] + ans[r][1] == 0){
return r;
}
r--;
}
return find(l, r);
}
