#include <bits/stdc++.h>
using namespace std;
int n, a[1100];
int sqr(int x) { return x * x; }
int main()
{
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
    int mx = 0, mi = 200;
    for (int i = 1; i <= n; i++)
    {
        mx = max(mx, a[i]);
        mi = min(mi, a[i]);
    }
    int ans = (1 << 30);
    for (int i = mi; i <= mx; i++)
    {
        int s = 0;
        for (int j = 1; j <= n; j++)
        {
            if (a[j] < i) s += sqr(i - a[j]);
            if (a[j] > i + 17) s += sqr(a[j] - (i + 17));
        }
        ans = min(ans, s);
    }
    printf("%d\n", ans);
    return 0;
}