#include <iostream>
#include <cstdio>

using namespace std;

#define forn(i, n) for(int i = 0; i < (int) (n); i++)
#define forsn(i, s, n) for(int i = (s); i < (int) (n); i++)
#define SQR(x) ((x)*(x))

const int INF = 200000000;
int dp[1001][1001];
int cost[1001][1001];

int n, b;

int calc(int s, int m){
	if(m == 0) return cost[s][m];

	if(dp[s][m] == -1){
		dp[s][m] = INF;
		forsn(i, s+1, n)
			dp[s][m] = min(dp[s][m], cost[s][i] + calc(i, m-1));
	}

	return dp[s][n];
}

int main(){
#ifdef ACM
	freopen("test.in", "r", stdin);
#endif

	while(scanf("%d %d", &n, &b) && !(n == 0 || b == 0)){
		int depot[1001];

		forn(i, n) scanf("%d", &depot[i]);

		int acum[1001], sacum[1001];

		acum[0] = sacum[0] = 0;
		forsn(i, 1, n+1){
			acum[i] += depot[i-1];
			sacum[i] += depot[i-1]*depot[i-1];
		}

		forn(i, n+1) forsn(j, i+1, n+1)
			cost[i][j] = (SQR(acum[j]-acum[i]) - (sacum[j]-sacum[i]))/2;

		cout << calc(0, b) << endl;
	}
	return 0;
}