#include "books.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;
bool odw[1'000'001];
int seg_ind[1'000'001];
vector<pii> segs;
int used_poz[1'000'001];
int rep_[1'000'001];
int min_c[1'000'001];
int max_c[1'000'001];
int fint(int v)
{
if(rep_[v] == v) return v;
rep_[v] = fint(rep_[v]);
return rep_[v];
}
void onion(int a, int b)
{
a = fint(a);
b = fint(b);
max_c[b] = max(max_c[a],max_c[b]);
min_c[b] = min(min_c[a],min_c[b]);
rep_[a] = b;
}
ll minimum_walk(vi p, int s)
{
int n = siz(p);
ll ans = -2;
rep(i,n)
{
if(odw[i] == 0)
{
int cur = i;
vi ls;
while(odw[cur] == 0)
{
ls.pb(cur);
odw[cur] = 1;
ans += abs(cur-p[cur]);
cur = p[cur];
}
int min_ = 1e9;
int max_ = -1e9;
forall(it,ls)
{
min_ = min(min_,it);
max_ = max(max_,it);
}
segs.pb({min_,max_});
forall(it,ls)
{
seg_ind[it] = siz(segs)-1;
}
}
}
if(ans == -2) return 0;
rep(i,siz(segs))
{
rep_[i] = i;
min_c[i] = segs[i].ff;
max_c[i] = segs[i].ss;
}
rep(i,siz(segs))
{
rep(j,siz(segs))
{
if(segs[i].ss > segs[j].ff && segs[i].ff < segs[j].ff)
{
onion(i,j);
}
}
}
vector<pair<int,pii>> se;
rep(i,siz(segs))
{
if(fint(i) == i)
{
se.pb({max_c[fint(i)] - min_c[fint(i)],{min_c[fint(i)],max_c[fint(i)]}});
}
}
sort(all(se));
reverse(all(se));
forall(it,se)
{
if(used_poz[it.ss.ff] == 0)
{
ans+=2;
rep2(i,it.ss.ff,it.ss.ss)
{
used_poz[i] = 1;
}
}
}
int pref = 0;
int suf = 0;
rep(i,n)
{
if(p[i] == i) pref++;
else break;
}
for(int i = n-1; i >= 0; i--)
{
if(p[i] == i) suf++;
else break;
}
return ans-suf*2;
}
