#include "books.h"
#include <bits/stdc++.h>
using namespace std;
#define FAST_IO ios_base::sync_with_stdio(0); cin.tie(nullptr)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define REP(n) FOR(O, 1, (n))
#define pb push_back
#define f first
#define s second
typedef long double ld;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef vector<int> vi;
typedef vector<pii> vii;
typedef vector<ll> vl;
typedef vector<piii> viii;
const int MAXN = 1000100;
int n;
//ll d[1100][1100];
/*int par[MAXN], sz[MAXN];
int find (int a) {return par[a] = par[a]==a ? a : find(par[a]);}
bool same (int a, int b) {return find(a) == find(b);}
void unite (int a, int b) {
a = find(a), b = find (b);
if (a == b) return;
par[b] = a;
sz[a] += sz[b];
}*/
//vector<pair<ll, pii>> edges;
int pref[MAXN];
long long minimum_walk(std::vector<int> p, int s) {
n = (int)p.size();
ll ret = 0ll;
FOR(i,0, n-1) ret += abs(i - p[i]);
FOR(i, 0, n-1) pref[min(i,p[i])]++, pref[max(i,p[i])]--;
FOR(i, 1, n-1) pref[i] += pref[i-1];
ll cur = 0ll;
FOR(i, 0, n-1) {
if (pref[i] == 0) cur++;
else {
ret += 2*cur;
cur = 0ll;
}
}
return ret;
}
