hdu 1421

#include <cstdio>
#include <algorithm>
int a[2001];
int dp[2001][1001]={0};
using namespace std;
int main()
{ int n,k,i=1,j=1;
while(scanf("%d %d",&n,&k)==2){

for(i=1;i<=n;i++)
scanf("%d",&a[i]);
sort(a+1,a+n+1);

for(i=2;i<=n;i++)
for(j=1;j<=i/2;j++){
if(i==j*2) dp[i][j]=dp[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]);
if(i>2*j) dp[i][j]=min(dp[i-1][j],dp[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]));
}
printf("%d\n",dp[n][k]);} 
return 0;
}