#include <iostream>
#include <cmath>
#include <algorithm>
using namespace std;
int main() {
	cin.tie(0); ios::sync_with_stdio(false);
	int N; cin >> N;
	int A[500] = { 0 };
	int sum = 0,key;
	int p = 0, ans = 9999, count = 1;
	for (int i = 0; i < N; i++) {
		cin >> A[i];
		sum += A[i];
	}
	key = sqrt(sum);
	for (int i = 0;i < N ; i++) {
		for (int j = i; j < i + 2*key - 1; j++) {
			if (count - A[j] > 0) {
				p += (count - A[j]);
			}
			if (j < i + key - 1) { count++; }
			else { count--; }
		}
		count = 1;
		p += (sum - key*key);
		ans = min(ans, p);
		p = 0;

		if (i + key >= N) { break; }
	}
	cout << ans << endl;
	return 0;
}