#include<bits/stdc++.h>
using namespace std;
const int N = 1005;
int n,ans = 1e7,ji,num[N];
int main()
{
cin>>n;
for(int i = 1;i <= n;i ++) cin>>num[i];
for(int i = 0;i <= 100;i ++) //枚举最低峰
{
ji = 0;
for(int j = 1;j <= n;j ++)
if(num[j] <= i) ji += pow(i - num[j],2); //该山峰比我要枚举的最低峰要低
else ji += pow(max(num[j] - i,17) - 17,2); //该山峰比最低峰高超过17
ans = min(ans,ji);
}
cout<<ans;
}