#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
//#define INF 9223372036854775807
#define LL long long
LL weight[2005];
LL dp[2005][1002]; ///前i个中找j对的最小值
int main()
{
    int n,k;
    while(scanf("%d%d",&n,&k)!=EOF)
    {
        for(int i=1; i<=n; i++)
            scanf("%I64d",&weight[i]);
        sort(weight+1,weight+n+1);
        for(int i=2; i<=n; i++)
            for(int j=1; 2*j<=i; j++)
            {
                if(j*2<=i-1)
                    dp[i][j]=min(dp[i-1][j],dp[i-2][j-1]+(weight[i]-weight[i-1])*(weight[i]-weight[i-1]));
                else
                    dp[i][j]=dp[i-2][j-1]+(weight[i]-weight[i-1])*(weight[i]-weight[i-1]);
            }
        printf("%I64d\n",dp[n][k]);
    }
    return 0;
}