#include <stdio.h>
#include <stdlib.h>
#include "gap.h"
#include<bits/stdc++.h>
#define INF 1e18
#define fi first
#define se second
#define FOR(i, k, n) for(ll i = k; i <= n; i++)
#define FOR1(i, k, n) for(ll i = k; i >= n; i--)
#define pb push_back
#define fastio ios::sync_with_stdio(0); cin.tie(0); cout.tie(0)
#define vi vector<int>
#define pii pair<int, int>
#define vii vector<pii>
#define ll long long
#define vll vector<ll>
#define pll pair<ll, ll>
#define re return 0
#define mii map<int, int>
#define input "chinaflu.inp"
#define output "chinaflu.out"
#define rf freopen(input, "r", stdin); freopen(output, "w", stdout)
using namespace std;
const int maxn = 1e5 + 5;
const int mod = 1e9 + 9;
const int base = 998244353;
void add(int &a, int b)
{
a += b;
if(a >= mod) a -= mod;
if(a < 0) a += mod;
}
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
int rand(int l, int r)
{
return uniform_int_distribution<int>(l, r) (rd);
}
ll a[maxn];
ll findGap(int sub, int n)
{
if(sub == 1)
{
ll minn = -1, maxx = -1;
ll l = 0, r = 1e18;
int d = 1, c = n;
while(d <= c)
{
minn = -1;
maxx = -1;
MinMax(l, r, &minn, &maxx);
a[d] = minn;
a[c] = maxx;
l = minn + 1;
r = maxx - 1;
d++;
c--;
}
ll ans = 0;
FOR(i, 1, n - 1)
ans = max(ans, a[i + 1] - a[i]);
return ans;
}
ll minn = -1, maxx = -1;
MinMax(0, 1e18, &minn, &maxx);
ll tb = maxx - minn;
tb = tb / (n - 1) + (tb % (n - 1) != 0);
ll l = 0;
int cnt = 0;
vector<pll> vv;
FOR(i, 1, n - 1)
{
MinMax(l, l + tb - 1, &minn, &maxx);
vv.pb({minn, maxx});
l = l + tb;
if(minn == -1)
cnt++;
}
if(!cnt)
{
return tb;
}
ll ans = 0;
ll tmp = 1e18;
for(auto x : vv)
{
if(x.fi == -1)
{
continue;
}
ans = max(ans, x.fi - tmp);
tmp = x.se;
}
return ans;
}
