#include "books.h"
#include<bits/stdc++.h>
using namespace std;
long long minimum_walk(std::vector<int> p, int s) {
int n = p.size();
vector<int> vis(n);
int last = 0;
long long ans = 0;
for(int i = 0; i < n; i++) if (!vis[i]) {
last = i;
int cur = i;
vis[cur] = 0;
int pre = cur;
cur = p[cur];
while (!vis[cur]) {
vis[cur] = 1;
ans += abs(pre - cur);
pre = cur;
cur = p[cur];
}
}
ans += last * 2;
return ans;
}
#ifdef ngu
int main() {
freopen ("task.inp", "r", stdin);
freopen ("task.out", "w", stdout);
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;
}
#endif // ngu
