#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int>vi;
#define pb push_back
#define sz(x) (int)x.size()
#define all(x) begin(x),end(x)
typedef pair<int,int>pi;
#define fi first
#define se second
typedef vector<pi>vpi;
#define eb emplace_back
#define FOR(i,a,b) for(int i=a; i<b; i++)
#define ROF(i,a,b) for(int i=b-1; i>=a; i--)
//--------------------------------
const int MX=1e6+5;
int N;
vi a;
ll minimum_walk(vi p, int s){
N=sz(p);
a.resize(N);
FOR(i,0,N) a[i]=i;
ll ans=0,cur=s;
while(1){
vpi vec;
FOR(i,0,N) if(p[a[i]]>i) vec.eb(i,a[i]);
if(!sz(vec)) break;
int rgt=p[vec.back().fi];
vec.eb(rgt,a[rgt]);
/*for(auto x: vec) cout << x.fi << ' ' << x.se << endl;
break;*/
int emp=vec[0].fi;
vpi vecc;
vecc.eb(emp,a[emp]);
FOR(i,emp+1,N){
if(p[a[i]]<i) vecc.eb(i,a[i]);
}
/*for(auto x: vecc) cout << x.fi << ' ' << x.se << endl;
break;*/
ROF(i,0,sz(vec)-1){
a[vec[i+1].fi]=vec[i].se;
}
FOR(i,1,sz(vecc)){
a[vecc[i-1].fi]=vecc[i].se;
}
/*for(auto x: a) cout << x << ' ';
cout << endl;*/
ans+=abs(cur-rgt);
ans+=abs(rgt-emp);
cur=emp;
}
ans+=abs(cur-s);
return ans;
}
/*
4 0
0 2 3 1
*/
