#include <bits/stdc++.h>
#include "gap.h"
using namespace std;
#define ll long long
#define sz size()
#define ff first
#define ss second
#define pb push_back
#define pii pair <int, int>
#define dur exit(0)
#define dur1 return(0)
//const int N = 2e5 + 5;
int n;
//static void my_assert(int k){ if (!k) exit(1); }
//static int subtask_num, N;
//static long long A[100001];
//static long long call_count;
//
//void MinMax(long long s, long long t, long long *mn, long long *mx) {
// int lo = 1, hi = N, left = N+1, right = 0;
// my_assert(s <= t && mn != NULL && mx != NULL);
// while (lo <= hi){
// int mid = (lo+hi)>>1;
// if (A[mid] >= s) hi = mid - 1, left = mid;
// else lo = mid + 1;
// }
// lo = 1, hi = N;
// while (lo <= hi){
// int mid = (lo+hi)>>1;
// if (A[mid] <= t) lo = mid + 1, right = mid;
// else hi = mid - 1;
// }
// if (left > right) *mn = *mx = -1;
// else{
// *mn = A[left];
// *mx = A[right];
// }
// if (subtask_num == 1) call_count++;
// else if (subtask_num == 2) call_count += right-left+2;
//}
long long findGap(int T, int N) {
n = N;
ll st, fn;
MinMax (0, 1e18, &st, &fn);
ll y = (fn - st - 1 + n - 2) / (n - 1);
vector <ll> q;
q.pb (st);
for (ll i = st + 1; i < fn; i += y) {
ll a, b;
MinMax (i, i + y - 1, &a, &b);
if (a != -1)
q.pb (a);
if (b != -1)
q.pb (b);
}
q.pb (fn);
ll ret = 0;
for (int i = 0; i < (int)q.sz - 1; ++i) {
ret = max (ret, q[i + 1] - q[i]);
}
return ret;
}
//int main() {
// freopen ("input.txt", "r", stdin);
// FILE *in = stdin, *out = stdout;
// my_assert(2 == fscanf(in, "%d%d", &subtask_num, &N));
// my_assert(1 <= subtask_num && subtask_num <= 2);
// my_assert(2 <= N && N <= 100000);
// for (int i=1;i<=N;i++) my_assert(1 == fscanf(in, "%lld", A+i));
// for (int i=1;i<N;i++) my_assert(A[i] < A[i+1]);
// fprintf(out, "%lld\n", findGap(subtask_num, N));
// fprintf(out, "%lld\n", call_count);
//}
