#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define rep(i,n) for(int (i)=0;(i)<(n);(i)++)

int main() {
  int n;
  cin >> n;
  vector<int> freq(n+1,0);
  rep(_i, n) {
    int a;
    cin >> a;
    freq[a]++;
  }
  vector<int> missing;
  vector<int> dups;
  int k = 0;
  for(int i=1; i<=n; i++) {
    if(freq[i]>1) {
      while(freq[i]!=1) {
	dups.push_back(i);
	freq[i]--;
      }
    } else if(freq[i]==0) {
      missing.push_back(i);
      k++;
    }
  }
  int ans = 0;
  rep(i,k) {
    ans += abs(missing[i]-dups[i]);
  }
  cout << ans << endl;
  return 0;
}