#include <bits/stdc++.h>
#include "gap.h"
#define debug(x) cerr << #x << " " << x << "\n"
#define debugs(x) cerr << #x << " " << x << " "
using namespace std;
typedef long long ll;
typedef pair <int, int> pii;
typedef pair <long double, pii> muchie;
const ll NMAX = 100001;
const ll VMAX = 1000001;
const ll INF = (1LL << 60);
const ll MOD = 90000000000000001;
const ll BLOCK = 1000000;
const ll base = 1000000001;
const ll nr_of_bits = 16;
ll a[100002];
long long findGap(int T, int N)
{
a[0] = -1;
a[N + 1] = 1e18;
a[N + 1] += 1;
if(T == 1){
int st = 1, dr = N;
while(st <= dr){
MinMax(a[st - 1] + 1, a[dr + 1] - 1, &a[st], &a[dr]);
st++;
dr--;
}
ll maxim = 0;
for(int i = 2; i <= N; i++){
maxim = max(maxim, a[i] - a[i - 1]);
}
return maxim;
}
ll first, last;
MinMax(0, 1e18, &first, &last);
ll BLOCK = last - first - 1;
BLOCK /= (N - 1);
ll ultim = first, maxim = 0, cnt = N - 1;
for(ll i = first + 1; i < last; i += BLOCK){
ll prim, doi;
cnt--;
MinMax(i, i + BLOCK - 1, &prim, &doi);
if(ultim != -1 && prim != -1)
maxim = max(maxim, prim - ultim);
if(doi != -1)
ultim = doi;
}
maxim = max(maxim, last - ultim);
return maxim;
}
