#include <bits/stdc++.h>
//#include "books.h"
using namespace std;
#define ll long long
#define vb vector<bool>
#define pb push_back
#define ff(aa, bb, cc) for(ll aa = bb; aa < cc; aa++)
#define vl vector<ll>
#define pll pair<ll, ll>
#define fi first
#define se second
#define ed "\n"
#define all(aaa) aaa.begin(), aaa.end()
#define rall(aaa) aaa.rbegin(), aaa.rend()
ll MOD = 1e9+7;
long long minimum_walk(std::vector<int> P, int s){
vl p;
ll n = P.size();
ff(i, 0, n){
p.pb(P[i]);
}
if(n == 1){
return 0;
}
if(n == 2){
vl x = {1, 0};
if(p == x){
return 2;
}
return 0;
}
if(n == 3){
vl x = {0, 1, 2};
if(p == x){
return 0;
}
x = {1, 0, 2};
if(p == x){
return 2;
}
return 4;
}
if(n == 4){
vl x = {0, 1, 2, 3};
if(p == x){
return 0;
}
x = {1, 0, 2, 3};
if(p == x){
return 2;
}
x = {3, 2, 1, 0};
if(p == x){
return 10;
}
x = {1, 0, 3, 2};
vl y = {2, 3, 1, 0};
vl z = {3, 2, 0, 1}, aa = {2, 3, 0, 1};
if(p == x || p == y || p == z || p == aa){
return 8;
}
vector<vl> c4;
c4.pb({0, 2, 1, 3});
c4.pb({1, 2, 0, 3});
c4.pb({2, 0, 1, 3});
c4.pb({2, 1, 0, 3});
ff(i, 0, c4.size()){
if(p == c4[i]){
return 4;
}
}
return 6;
}
return 0;
}
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;
}
