1 /*
 2     PROB:skidesign
 3     ID:wanghan
 4     LANG:C++
 5 */
 6 #include "iostream"
 7 #include "cstdio"
 8 #include "cstring"
 9 #include "algorithm"
10 #include "cmath"
11 using namespace std;
12 const int maxn=1000+10;
13 const int INF=1<<28;
14 int a[maxn];
15 int n;
16 int main()
17 {
18     freopen("skidesign.in","r",stdin);
19     freopen("skidesign.out","w",stdout);
20     cin>>n;
21     for(int i=1;i<=n;i++)
22         cin>>a[i];
23     int res=INF;
24     for(int  i=0;i<=100-17;i++){
25         int ans=0;
26         for(int j=1;j<=n;j++){
27             if(a[j]>=i&&a[j]<=i+17){
28                 
29             }else{
30                 int num=min(abs(i-a[j]),abs(i+17-a[j]));
31                 ans+=num*num;
32             }
33         }
34         res=min(ans,res);
35     }
36     cout<<res<<endl;
37 }