#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll INF = 1e9;
ll MOD = 998244353;
typedef pair<ll,ll> ii;
#define iii pair<int,int>
#define f(i,a,b) for(ll i = a;i < b;i++)
#define pb push_back
#define vll vector<ll>
#define F first
#define S second
#define all(x) (x).begin(), (x).end()
///I hope I will get uprating and don't make mistakes
///I will never stop programming
///sqrt(-1) Love C++
///Please don't hack me
///@TheofanisOrfanou Theo830
///Think different approaches (bs,dp,greedy,graphs,shortest paths,mst)
///Stay Calm
///Look for special cases
///Beware of overflow and array bounds
///Think the problem backwards
///Training
#include "books.h"
long long minimum_walk(std::vector<int> p, int s) {
ll ans = 0;
ll n = p.size();
bool v[n] = {0};
ll dist = 0;
ll l[n],r[n];
vector<ii>rang;
f(i,0,n){
if(p[i] != i && !v[i]){
ll last = i;
ll st = i;
ll pos = p[i];
v[i] = 1;
l[st] = i,r[st] = pos;
while(pos != st){
l[st] = min(l[st],pos);
r[st] = max(r[st],pos);
v[pos] = 1;
ans += abs(pos - last);
last = pos;
pos = p[pos];
}
ans += abs(pos - last);
l[st] = min(l[st],pos);
r[st] = max(r[st],pos);
rang.pb(ii(l[st],r[st]));
}
}
if(rang.empty()){
return ans;
}
sort(all(rang));
dist = max(0LL,rang[0].F - s);
ll maxi = s;
ll mini = s;
f(i,0,(1LL * rang.size())-1){
maxi = max(maxi,rang[i].S);
if(rang[i].S >= s){
mini = min(mini,rang[i].F);
}
if(maxi < rang[i+1].F){
dist += rang[i+1].F - maxi;
}
}
if(rang.back().S >= s){
mini = min(mini,rang.back().F);
}
ans += 2 * dist;
dist = 0;
for(ll i = rang.size()-1;i >= 1;i--){
mini = min(mini,rang[i].F);
if(mini > rang[i-1].S){
dist += mini - rang[i-1].S;
}
}
ans += 2 * dist;
return ans;
}
/*
int main() {
int n, s;
assert(2 == scanf("%d %d", &n, &s));
vector<int> p((unsigned) n);
for(int i = 0; i < n; i++)
assert(1 == scanf("%d", &p[(unsigned) i]));
long long res = minimum_walk(p, s);
printf("%lld\n", res);
return 0;
}
*/
/*
4 0
0 2 3 1
*/
