#include "bits/stdc++.h"
#include "prize.h"
// #include "grader.cpp"
using namespace std;
int find_best(int n) {
int x = 0;
vector <int> v = ask(x), v1, v2;
while(1) {
int l = x, r = n-1, k1 = (int(sqrt(n) / 2)), k = k1;
if(v[0] + v[1] == 0) return x;
while(x + k < n) {
if(ask(k + x) == v) l = x + k;
else {
r = k + x;
break;
}
k += k1;
}
while(l <= r) {
int md = (l + r) / 2;
v1 = ask(md);
if(v1[0] + v1[1] == 0) return md;
if(v1 == v) l = md+1;
else r = md-1, x = md, v2 = v1;
}
v = v2;
}
assert(0);
}
