#ifndef _Pbrngw_
#include "gap.h"
#endif // _Pbrngw_
#include<bits/stdc++.h>
using namespace std;
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i--)
#define fi first
#define se second
#define pb push_back
#define ALL(a) (a).begin(), (a).end()
#define task "kbsiudthw"
typedef vector<int> vi;
typedef pair<int, int> ii;
typedef pair<int, ii> pii;
const int N = 1e5 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 2277;
long long findGap(int T, int N)
{
if (T == 1){
vi A;
long long x = 0, y = 1e18;
MinMax(0, 1e18, &x, &y);
A.pb(x); A.pb(y);
while (y - x > 1){
MinMax(x+1, y - 1, &x, &y);
if(x == -1) break;
A.pb(x);
if (x != y)
A.pb(y);
}
sort(ALL(A));
int ans = 0;
FOR (i, 0, N - 2) ans = max(ans, A[i+1] - A[i]);
return ans;
}
long long A, B, C1, C2;
MinMax(0, 1e18, &A, &B);
if (N == 2) return B - A;
long long block = (B - A - 1)/(N - 2);
if ((B - A - 1)%(N-2)) ++block;
long long last = A, ans = 0;
for (long long i = A+1; i < B; i += block){
long long x, y;
MinMax(i, min(B - 1, i + block - 1), &x, &y);
if (x == -1) continue;
ans = max(ans, x - last);
last = y;
}
ans = max(ans, B - last);
return ans;
}
#ifdef _Pbrngw_
signed main(){
ios_base::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
if (fopen(task".inp", "r")){
freopen(task".inp", "r", stdin);
freopen(task".out", "w", stdout);
}
return 0;
}
#endif // _Pbrngw_
