#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 2e4 + 100; 
int n,m;
int a[N];
int beginning;
int temp;
int ans = INT_MAX;
signed main(){
	cin>>m>>n;
	for(int i = 1;i<=m;i++){
		cin>>a[i];
	}
	sort(a+1,a+1+n);
	beginning = 1;
	while(beginning + 2*n <= m+1){
		temp = 0;
		for(int i = beginning;i<=n+beginning-1;i++){
			temp += (a[2*i-1] - a[2*i]) * (a[2*i-1] - a[2*i]);
		}
		ans = min(ans,temp);
		beginning++;
	}
	cout<<ans;
	return 0;
}

改好必关