#include "books.h"
#include <bits/stdc++.h>
#define pb push_back
#define x first
#define y second
#define all(a) a.begin(), a.end()
#define sz(a) (int)a.size()
#define rd() abs((int)rng())
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
const int maxn = 1e6 + 100;
const int mod = 1e9 + 7;
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int n, s, val[maxn], nxt, L[maxn], R[maxn];
ll base, add;
vector<int>p;
ll minimum_walk(vector<int>perm, int S)
{
p = perm;
s = S;
n = sz(p);
for(int i = 1; i <= n; i++)
L[i] = mod, R[i] = -mod;
while(n > 0 && p[n - 1] == n - 1)
--n;
for(int i = 0; i < n; i++)
{
if(val[i] == 0)
{
int col = ++nxt, cur = i;
while(val[cur] == 0)
{
val[cur] = col;
L[col] = min(L[col], cur);
R[col] = max(R[col], cur);
base += abs(p[cur] - cur);
cur = p[cur];
}
}
}
vector<int>ends[n];
for(int i = 1; i <= nxt; i++)
{
ends[L[i]].pb(+1);
ends[R[i]].pb(-1);
}
int open = 0;
for(int i = 0; i < n; i++)
{
for(int d : ends[i])
open += d;
if(i != n - 1 && open == 0)
add++;
}
return base + add * 2;
}
/*int main()
{
ios_base::sync_with_stdio(false), cin.tie(0);
vector<int>perm;
ifstream fin("in.txt");
int n, s;
fin >> n >> s;
perm.resize(n);
for(int i = 0; i < n; i++)
fin >> perm[i];
cout << minimum_walk(perm, s) << endl;
return 0;
}*/
