#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pi;
typedef pair<ll,ll> pl;
#define endl '\n'
#define F first
#define S second
#define all(x) (x).begin(),(x).end()
const int N = 3e5+1;
const ll INF = 2e18;
const int MOD = 1e9+7;
vector<int> ask(int i);
vector<vector<int> > memo(N);
const int block = 5;
int nn;
int queried = 0;
vector<int> askme(int i){
if(memo[i].empty()){
queried++;
assert(queried <= 10000);
memo[i] = ask(i);
}
return memo[i];
}
int seen,cheap;
int go(int b){
for(int i=b*block;i<min(nn,(b+1)*block);i++){
vector<int> arr = askme(i);
if(arr[0] + arr[1] == 0)
return i;
if(arr[0] + arr[1] < cheap)
seen++;
}
return -1;
}
int find_best(int n) {
/// the second to smallest price is in at most 450 boxes
/// the maximum amount of prizes is 5
nn = n;
int blocks = (n+4)/5;
for(int i=0;i<min(460,n);i++){
vector<int> arr = askme(i);
cheap = max(cheap,arr[0] + arr[1]);
}
int L = 0,R = blocks-2;
while(L<=R){
int l = L,r = R;
int target = -1;
while(l<=r){
int mid = (l+r)/2;
int low,high,pos;
pos = (mid+1)*block;
vector<int> arr = askme(pos);
low = arr[0],high = arr[1];
if(low + high == 0)
return pos;
if(low + high < cheap){
bool chk = 0;
arr = askme(pos-1);
if(arr[0] + arr[1] < cheap || arr[0] - seen > 0)
chk = 1;
if(arr[0] + arr[1] == 0)
return pos-1;
if(chk){
target = mid;
r = mid-1;
}
else{
target = mid+1;
break;
}
continue;
}
if(low - seen > 0){
target = mid;
r = mid-1;
}
else
l = mid+1;
}
if(target == -1)
target = blocks-1;
int ans = go(target);
if(ans != -1)
return ans;
L = target+1;
}
int ans = go(blocks-1);
if(ans != -1)
return ans;
assert(0);
return 0;
}
