#include <bits/stdc++.h>
using namespace std;
int n;
typedef long long ll;
void MinMax(ll, ll, ll*, ll*);
ll ceil(ll x, ll d) {
return (x - 1) / d + 1;
}
ll solve_naive() {
ll l = 0, r = 1000000000000000000LL;
vector<ll> v;
int lim = (n + 1) / 2;
for(int i=1; i<=lim; i++) {
ll x, y;
MinMax(l, r, &x, &y);
v.push_back(x);
if(x != y) v.push_back(y);
l = x + 1;
r = y - 1;
}
sort(v.begin(), v.end());
ll ret = 0;
for(int i=1; i<(ll)v.size(); i++) {
ret = max(ret, v[i] - v[i-1]);
} return ret;
}
ll solve_proway() {
ll L = 0, R = 1e18;
MinMax(L, R, &L, &R);
if(n == 2) return R - L;
ll big = ceil(R - L - 1, (ll)n-2);
ll small = (R - L - 1) / (n - 2);
ll big_cnt = (R - L - 1) % (n-2);
ll small_cnt = (n - 2) - big_cnt;
vector<pair<ll, ll>> v;
ll nxt = L;
for(ll i=1, l = L+1; i<=big_cnt; i++, l += big) {
ll r = l + big - 1;
ll x, y;
MinMax(l, r, &x, &y);
if(x != -1) {
v.push_back(make_pair(x, y));
} nxt = r+1;
}
for(ll i = 1, l = nxt; i <= small_cnt; i++, l += small) {
ll r = l + small - 1;
ll x, y;
MinMax(l, r, &x, &y);
if(x != -1) {
v.push_back(make_pair(x, y));
}
}
int tot = 2;
for(pair<ll, ll> b : v) {
if(b.first == b.second) tot++;
else tot += 2;
}
if(tot == n) {
ll ret = 0;
ret = max(ret, v[0].first - L);
ret = max(ret, R - v.back().second);
for(int i=0; i<v.size(); i++) {
ret = max(ret, v[i].second - v[i].first);
}
for(int i=1; i<v.size(); i++) {
ret = max(ret, v[i].first - v[i-1].second);
}
return ret;
}
else {
ll ret = 0;
ret = max(ret, v[0].first - L);
ret = max(ret, R - v.back().second);
for(int i=1; i<v.size(); i++) {
ret = max(ret, v[i].first - v[i-1].second);
} return ret;
}
}
long long findGap(int32_t T, int32_t N)
{
n = N;
if(T == 1) return solve_naive();
else return solve_proway();
return 0;
}
