#include <bits/stdc++.h>
#include "gap.h"
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <functional>
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
//Dijkstra->set
//set.find_by_order(x) x-position value
//set.order_of_key(x) number of strictly less elements don't need *set.??
#define N 100005
#define wr cout << "Continue debugging\n";
#define all(x) (x).begin(), (x).end()
#define ll long long int
#define pii pair <int, int>
#define pb push_back
#define ff first
#define ss second
const ll inf = 1e18;
ll a[N];
ll findGap(int t, int n)
{
// if (t == 1){
// int l = 1, r = n;
// ll mn = 0, mx = 1e18, ans = 0;
// while(l <= r){
// ll s = mn, t = mx;
// MinMax(s, t, &mn, &mx);
// a[l] = mn;
// a[r] = mx;
// if (l > 1) ans = max(ans, a[l]-a[l-1]);
// if (r < n) ans = max(ans, a[r+1]-a[r]);
// l++;
// r--;
// mn++;
// mx--;
// }
// if (n == 2) return a[2]-a[1];
// return ans;
// }
// ll mn, mx;
// MinMax(0, 1e18, &mn, &mx);
ll l = 0, r = 1e18, ans = 0;
while (l < r){
ll md = (l+r)/2;
ll mn, mx, mn1, mx1, x = -inf, y = -inf;
MinMax(l, md, &mn, &mx);
mn1 = mn; mx1 = mx;
if (mn1 != -1) x = mx1-mn1+1;
MinMax(md+1, r, &mn, &mx);
if (mn != -1) y = mx-mn+1;
if (mx1 != -1 and mn != -1) ans = max(ans, mn-mx1);
if (x > y) r = md;
else l = md + 1;
}
return ans;
}
// int main ()
// {
// ios::sync_with_stdio(false);
// cin.tie(0);
// cin >> t;
// while (t--){
// }
// }
