bonecas

#include<bits/stdc++.h>
using namespace std;
#define all(x) x.begin(),x.end()
#define pb push_back
#define fr first
#define sc second
#define mp make_pair
#define int long long

const int maxn = 1e4+10;
const int maxk = 3e3+10;
const int inf = 1e18+10;

int n, k, a[maxn], dp[maxn][maxk];



void solve() {

    cin >> n >> k;
    for(int i = 1; i <= n; i++) cin >> a[i];

    sort(a+1,a+1+n,greater<int>());

    dp[1][0] = 0;
    for(int j = 1; j <= k; j++) dp[1][j] = inf;
    for(int i = 2; i <= n; i++) {
        for(int j = 0; j <= k; j++) {
            if(3*j > i) dp[i][j] = inf;
            else {
                dp[i][j] = min(dp[i-1][j],dp[i-2][j-1]+(a[i]-a[i-1])*(a[i]-a[i-1]));
            }
        }
    }

    cout << dp[n][k] << endl;

}

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    //freopen("in.in","r",stdin);

    solve();
}