#include "books.h"
#include "bits/stdc++.h"
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> pii;
typedef vector<pii> vpii;
typedef vector<vpii> vvpii;
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
int N;
ll cost;
vi vis, P;
void cycle(int i, int &mini, int &maxi)
{
if (vis[i])
return;
mini = min(mini, i);
maxi = max(maxi, i);
vis[i] = 1;
cost += (ll)abs(P[i] - i);
cycle(P[i], mini, maxi);
}
long long minimum_walk(std::vector<int> p, int s)
{
N = sz(p);
P.resize(N);
for (int i = 0; i < N; ++i)
P[i] = p[i];
vis.assign(N, false);
cost = 0;
vpii borders;
for (int i = 0, mini, maxi; i < N; ++i)
{
if (!vis[i] && P[i] != i)
{
mini = maxi = i;
cycle(i, mini, maxi);
borders.push_back({mini, maxi});
}
}
sort(all(borders));
ll pos = s;
for (pii b : borders)
{
cost += 2 * max(0LL, b.first - pos);
pos = max(pos, b.second);
}
return cost;
}
