#include <iostream>
#include <cmath>
#include <cstdio>
#include  <cstdlib>
#include <map>
#include <stack>
#include <queue>
#include <cstdlib>
#include <vector>
#include <string>
#include <algorithm>
using namespace std;


int main()
{
	int n;
	vector<int> v;
	int a;
	int cnt = 0;

	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> a;
		v.push_back(a);
	}
	sort(v.begin(), v.end());

	for (int i = 0; i < n; i++) {
		while (v[i] != (i + 1)) {
			if (v[i] > i) v[i]--;
			else v[i]++;
			cnt++;
		}
	}
	cout << cnt << endl;


	return 0;
}