#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
const int N = 3e5+7;
vector<int> ans[N];
int rs=-1;
int gdl,gdr;
vector<int> get(int x){
if(ans[x].size()==0){
ans[x]=ask(x);
if(ans[x][0]==0&&ans[x][1]==0){
rs=x;
return ans[x];
}
if(ans[x][0]==0)gdl=max(gdl,x);
if(ans[x][1]==0)gdr=min(gdr,x);
// cout<<x<<" "<<ans[x][0]<<" "<<ans[x][1]<<endl;
}
return ans[x];
}
void fnd(int l,int r){
if(rs!=-1)return;
if(l==r){
if(gdl<=l&&l<=gdr)
get(l);
return;
}
if(l+1==r){
return;
}
int m=(l+r)/2;
if(gdl>=m){
fnd(m,r);
return;
}
if(gdr<=m){
fnd(l,m);
return;
}
vector<int> lres=get(l);
if(rs!=-1)return;
vector<int> rres=get(r);
if(rs!=-1)return;
if(lres[0]==rres[0]&&lres[1]==rres[1])return;
if(lres[1]==0||rres[0]==0)return;
vector<int> md=get(m);
if(rs!=-1)return;
if(rand()&1){
if(md[0]!=0)fnd(l,m);
if(rs!=-1)return;
if(md[1]!=0)fnd(m,r);
}
else{
if(md[1]!=0)fnd(m,r);
if(rs!=-1)return;
if(md[0]!=0)fnd(l,m);
}
}
int find_best(int n) {
srand(6451719);
gdl=-1;
gdr=n;
fnd(0,n-1);
return rs;
int i;
for(i = 0; i < n; i++) {
std::vector<int> res = get(i);
// cout<<i<<" ok "<<res[0]<<" "<<res[1]<<endl;
if(res[0] + res[1] == 0)
return i;
int cur=i;
int brd=20;
if(res[0]+res[1]<n/2)brd=3;
else brd=20;
for(int j=brd;j>=0;j--){
int rg=cur;
rg+=1<<j;
if(rg<n){
vector<int> cres=get(rg);
// cout<<rg<<" "<<cur<<" "<<j<<" ok "<<cres[0]<<" "<<cres[1]<<endl;
if(cres[0]+cres[1]==0)return rg;
if(res[0]==cres[0]&&res[1]==cres[1]){
cur=rg;
continue;
}
if(cres[0]==0){
cur=rg;
continue;
}
}
}
i=cur;
}
return n-1;
}
