#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int>vi;
#define pb push_back
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#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--)
void dbgv(vi vec){for(int x: vec) cout << x << ' '; cout << endl; }
//---------------------------
int N;
int dist(int i, int j){
return abs(i-j);
}
ll minimum_walk(vi p, int s) {
N=sz(p);
int l=0, r=N-1;
while(p[l]==l) l++;
while(p[r]==r) r--;
vi vec(N+1,0);
ll ans=0;
FOR(i,0,N){
ans+=dist(i,p[i]);
int x=i, y=p[i];
if(x>y) swap(x,y);
vec[x]++; vec[y]--;
}
FOR(i,1,N) vec[i]+=vec[i-1];
FOR(i,0,r){
if(i<l || !vec[i]) ans+=2;
}
return ans;
}
/*
4 0
0 2 3 1
*/
/*
3 0
2 0 1
*/
