// #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;
long long minimum_walk(std::vector<int> p, int s) {
n=sz(p);
ll cycles=0;
ll ans=0;
vll vis(n,0);
vll mxvals(n,-1);
rep(i,0,n) {
if(p[i]==i) continue;
ans+=abs(i-p[i]);
if(vis[i]) continue;
++cycles;
ll j=i;
ll mx=j;
while(!vis[j]) {
vis[j]=1;
j=p[j];
mx=max(mx,j);
}
mxvals[i]=mx;
}
ll mx=0;
//cout<<ans<<endl;
rep(i,0,n) {
//cout<<"i = "<<i<<" mxvals = "<<mxvals[i]<<endl;
if(mxvals[i]!=-1) {
//cout<<"i = "<<i<<" mx = "<<mx<<endl;
if(i) ans+=2*max(0LL,i-mx);
//cout<<123<<endl;
mx=max(mx,mxvals[i]);
}
}
//cout<<ans<<endl;
//cout<<cycles<<endl;
return ans;
}
/**
#include <cstdio>
#include <vector>
#include <cassert>
// BEGIN SECRET
#include <string>
// END SECRET7
x
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;
}
/**/
