#include <cstdio>#include <cstring>#include <algorithm>#include <climits>using namespace std;#define sq(x) ((x)*(x))const int maxn = 10005;const int maxm = 5005;int f[maxn][maxm], s[maxn][maxm];int val[maxn], n, m;int main() {	int T; scanf("%d", &T);	for(int kase = 1;kase <= T;kase++) {		scanf("%d%d", &n, &m); m--;		for (int i = 1; i <= n; i++) scanf("%d", &val[i]);		sort(val + 1, val + 1 + n);		for (int i = 1; i <= n; i++) {			f[i][0] = sq(val[i] - val[1]);			int sj = min(m, i - 1);			s[i][sj + 1] = i - 1;			for (int j = sj; j >= 1;j--) {				f[i][j] = INT_MAX / 3;				for (int k = s[i - 1][j]; k <= s[i][j + 1]; k++) {					if (f[k][j - 1] + sq(val[i] - val[k + 1]) < f[i][j]) {						f[i][j] = f[k][j - 1] + sq(val[i] - val[k + 1]);						s[i][j] = k;					}				}			}		}		printf("Case %d: %d\n", kase, f[n][m]);	}	return 0;}