// #pragma GCC target ("avx,avx2,fma")
// #pragma GCC optimize ("Ofast,inline") // O1 - O2 - O3 - Os - Ofast
// #pragma GCC optimize ("unroll-loops")
#include <bits/stdc++.h>
#include "books.h"
using namespace std;
#define rep(i, a, b) for (ll i = (a); i < (b); ++i)
#define per(i, a, b) for (ll i = (b) - 1; i >= (a); --i)
#define trav(a, x) for (auto &a : x)
#define all(x) x.begin(), x.end()
#define sz(x) (ll)x.size()
#define pb push_back
#define debug(x) cout<<#x<<" = "<<x<<endl
#define umap unordered_map
#define uset unordered_set
typedef pair<int, int> ii;
typedef pair<int, ii> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef long long ll;
typedef pair<ll,ll> pll;
typedef pair<ll,pll> ppll;
typedef vector<ll> vll;
typedef vector<pll> vpll;
typedef vector<vll> vvll;
const ll INF = 1'000'000'007;
ll n;
ll encode(vi p,ll pos) {
ll mul=1;
ll sum=0;
rep(i,0,n) {
sum+=mul*p[i];
mul*=n+1;
}
sum+=pos*mul;
return sum;
}
pair<vi,ll> decode(ll state) {
vi vec;
rep(i,0,n) {
vec.pb(state%(n+1));
state/=n+1;
}
return {vec,state};
}
long long minimum_walk(std::vector<int> p, int s) {
n=sz(p);
ll cycles=0;
ll ans=0;
vll vis(n,0);
rep(i,0,n) {
if(p[i]==i) continue;
ans+=abs(i-p[i]);
if(!vis[i]) ++cycles;
ll j=i;
while(!vis[j]) {
vis[j]=1;
j=p[j];
}
}
ll states=1;
rep(i,0,n+1) states*=n+1;
queue<ll> q;
vll dist(states,INF);
q.push(encode(p,0));
dist[encode(p,0)]=0;
while(!q.empty()) {
ll state=q.front();
q.pop();
vi books;
ll pos;
tie(books,pos)=decode(state);
ll d=dist[state];
ll holding=-1;
rep(i,0,n) if(books[i]==n) holding=i;
if(pos&&dist[encode(books,pos-1)]==INF) {
dist[encode(books,pos-1)]=d+1;
q.push(encode(books,pos-1));
}
if(pos+1<n&&dist[encode(books,pos+1)]==INF) {
dist[encode(books,pos+1)]=d+1;
q.push(encode(books,pos+1));
}
if(holding==-1) {
ll book=books[pos];
books[pos]=n;
if(dist[encode(books,pos)]==INF) {
dist[encode(books,pos)]=d;
q.push(encode(books,pos));
}
books[pos]=book;
}
if(holding!=-1) {
ll book=books[pos];
books[pos]=holding;
if(dist[encode(books,pos)]==INF) {
dist[encode(books,pos)]=d;
q.push(encode(books,pos));
}
books[pos]=book;
}
}
vi vec;
rep(i,0,n) vec.pb(i);
ll state=encode(vec,0);
ll ans2=dist[state];
//cout<<"ans = "<<ans<<" ans2 = "<<ans2<<endl;
//assert(ans==ans2);
ans+=2*(cycles-1);
return ans2;
}
/**
#include <cstdio>
#include <vector>
#include <cassert>
// BEGIN SECRET
#include <string>
// END SECRET7
using namespace std;
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;
}
/**/
