#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;

int main() {

	int n;
	cin >> n;
	vector<int> array;
	array.resize(n + 1, 0);
	for (int i = 0;i<n;i++) {
		int num;
		cin >> num;
		array[num]++;
	}

	int cost = n == 1 ? 0 : 10000;

	vector<int> target1;
	vector<int> target2;
	for (int i = 1;i < array.size();i++) {
		if (array[i]==0) {
			target2.push_back(i);
		}
		else if (array[i]>1) {
			for (int j = 0;j < array[i]-1;j++) {
				target1.push_back(i);
			}
		}
	}
	for (int i = 0;i < target1.size();i++) {
		vector<int> buf;
		copy(target1.begin(), target1.end(), back_inserter(buf));
		int calc = 0;
		for (int j = 0;j < target1.size();j++) {
			calc += abs(target2[j]-target1[j]);
		}
		cost = min(cost,calc);
		for (int j = 0;j < target1.size();j++) {
			if (j == 0)target1[j] = buf[target1.size() - 1];
			else {
				target1[j] = buf[j - 1];
			}
		}
	}

	cout << cost<<endl;

	
	return 0;
}