#include <iostream>
using namespace std;

const int MAX_N = 110;
const int END = 201;
int a[MAX_N];

int int_pow(int a, int b) {
    int res = 1;
    for (int i = 0; i < b; i++) res *= a;
    return res;
}

int main() {
    int n, sum = 0;
    cin >> n;

    for (int i = 0; i < n; i++) {
        cin >> a[i];
        sum += a[i];
    }

    int ans = (1 << 28);
    for (int w = END; w >= 1; w -= 2) {
        int use_block = int_pow((w + 1) / 2, 2);
        if (use_block > sum) continue;

        int cost = 0, missing = 0;
        for (int b_i = 0; b_i < END; b_i++) {
            int height = (b_i < w) ? min(1 + b_i, w - b_i) : 0,
                cur_height = b_i < n ? a[b_i] : 0;
            cost += abs(height - cur_height);
            if (height > cur_height) missing += height - cur_height;
        }
        ans = min(ans, cost - missing);
    }
    cout << ans << endl;

    return 0;
}