#include "gap.h"
#include <iostream>
#include <vector>
#include <deque>
#include <cassert>
#include <algorithm>
#include <tuple>
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(xs) xs.begin(), xs.end()
#define pb push_back
using namespace std;
typedef pair<long long, long long> P;
P query(long long s, long long t) {
long long mn, mx;
MinMax(s, t, &mn, &mx);
return P(mn, mx);
}
long long findGap(int T, int N) {
//if (T == 1 || N <= 8) {
if (T == 1 || N <= 10) {
long long lo = 0, hi = 1000000000000000000LL;
vector<long long> fr, br;
rep(_, (N+1)/2) {
long long a, b;
tie(a, b) = query(lo, hi);
lo = a+1, hi = b-1;
fr.pb(a);
if (a != b) br.pb(b);
}
reverse(all(br));
for (long long x : br) fr.pb(x);
//for (long long x: fr)cout<<x<<",";cout<<"\n";
long long m = 0;
rep(i, N-1) m = max(m, fr[i+1]-fr[i]);
return m;
}
else {
long long lo, hi;
tie(lo, hi) = query(0, 1000000000000000000LL);
long long m = 1, pos = lo+1;
while (pos+m < hi) {
//cout<<"pos="<<pos<<", m="<<m<<"\n";
long long a, b;
long long r = m+1;
while (true) {
tie(a, b) = query(pos, min(pos+r, hi));
//cout<<"query("<<pos<<","<<pos+r<<") -> ("<<a<<","<<b<<")\n";
if (a != -1) break;
r += r+1;
}
//cout<<"a="<<a<<", b="<<b<<"\n";
m = max(m, a-(pos-1));
pos = b+1;
}
return m;
}
return 0;
}
