#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
int const MAX = 2005;
int const INF = 0x3fffffff;
int dp[MAX][MAX], a[MAX], b[MAX];

int main()
{
    int n, k;
    while(scanf("%d %d", &n, &k) != EOF)
    {
        for(int i = 1; i <= n; i++)
            scanf("%d", &a[i]);
        sort(a + 1, a + n + 1);
        int sum = 0;
        for(int i = 1; i < n; i++)
            b[i] = (a[i + 1] - a[i]) * (a[i + 1] - a[i]);
        n --;
        for(int i = 0; i <= n; i++)
        {
            for(int j = 0; j <= k; j++)
                dp[i][j] = INF;
            dp[i][0] = 0;
        }
        dp[1][1] = b[1];
        for(int i = 2; i <= n; i++)
            for(int j = 1; j <= k; j++)
                    dp[i][j] = min(dp[i - 1][j], dp[i - 2][j - 1] + b[i]);
        printf("%d\n", dp[n][k]);
    }
}