#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	int a[20001] = {}, b[20001] = {};
	int n;
	cin >> n;
	int sum = 0;
	for (int i = 1; i <= n; i++) {
		cin >> a[i];
		sum += a[i];
	}
	int p = 1;
	while (p * p <= sum) {
		p++;
	}
	p--;
	int j = 1;
	for (int i = 1; i <= 2 * p - 1; i++) {
		b[i] = j;
		if (i < p) j++;
		else j--;
	}
	int ans = 0;
	for (int i = 1; i <= n; i++) {
		ans += max(0, a[i] - b[i]);
	}
	cout << ans << endl;
	return 0;
}