#include "books.h"
#include "bits/stdc++.h"
using namespace std;
#define fi first
#define se second
#define ll long long
#define dbg(v) cerr<<#v<<" = "<<v<<'\n'
#define vi vector<int>
#define vl vector <ll>
#define pii pair<int,int>
#define mp make_pair
#define db long double
#define pb push_back
#define all(s) s.begin(),s.end()
template < class T > T smin(T &a,T b) {if (a > b) a = b;return a;}
template < class T > T smax(T &a,T b) {if (a < b) a = b;return a;}
#include "books.h"
const int oo = 1e9;
int n;
int D1[20][1 << 20];
int D2[20][1 << 20];
int Log[1 << 20];
int get1(int l,int r) {
int k = Log[r - l + 1];
return min(D1[k][l],D1[k][r - (1 << k) + 1]);
}
int get2(int l,int r) {
int k = Log[r - l + 1];
return max(D2[k][l],D2[k][r - (1 << k) + 1]);
}
long long minimum_walk(std::vector<int> p, int s) {
n = p.size();
int a = 0,b = n - 1;
while (a + 1 <= s && p[a] == a)
--a;
while (b - 1 >= s && p[b] == b)
--b;
int l = s,r = s;
ll ans = 0;
for (int i = 0;i < n;++i)
ans += abs(i - p[i]);
for (int i = 0;i < n;++i) {
D1[0][i] = D2[0][i] = p[i];
}
for (int t = 1;t < 20;++t)
for (int i = 0;i + (1 << t) <= n;++i) {
D1[t][i] = min(D1[t - 1][i],D1[t - 1][i + (1 << (t - 1))]);
D2[t][i] = max(D2[t - 1][i],D2[t - 1][i + (1 << (t - 1))]);
}
for (int i = 2;i <= n;++i)
Log[i] = Log[i / 2] + 1;
while (a < l || r < b) {
while (get1(l,r) < l || r < get2(l,r)) {
smin(l,get1(l,r));
smax(r,get2(l,r));
}
if (l - 1 >= a) {
--l;
ans += 2;
}
if (r + 1 <= b) {
++r;
ans += 2;
}
}
return ans;
}
