package timus;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class p1167 {
    static int a[], totals[];
    static int h, s;
    static int min = Integer.MAX_VALUE;
    public static void main(String[] args) throws FileNotFoundException {
        InputStream is = System.in;
//        is = new FileInputStream(new File("A.txt"));
        FastScanner sc = new FastScanner(new InputStreamReader(is));
        h = sc.nextInt();
        s = sc.nextInt();
        int k[] = new int[h];
        for (int i=0; i<h; i++) {
            k[i] = sc.nextInt();
        }
        totals = new int[h+1];
        totals[1] = k[0];
        for (int i=2; i<h+1; i++) {
            totals[i]=totals[i-1]+k[i-1];
        }
        int maxcap = h-s+1;
        int unhappines[][] = new int[h+1][h+1];
        for (int i=1; i<=/*maxcap*/h; i++) {
            int up = Math.min(h, maxcap+i);
            for (int j=i; j<=up; j++) {
                int len = j-i+1;
                int ones = totals[j]-totals[i-1];
                unhappines[i][j] = (len-ones)*ones;
            }
        }
        int a[][] = new int[h+1][s+1];
        for (int i=1; i<=h; i++) {
            Arrays.fill(a[i], Integer.MAX_VALUE);
        }
        int maxes[] = new int[s+1];
        for (int i=1; i<=s; i++) {
            maxes[i] = maxcap+i-1;
        }
        for (int i=1; i<=maxcap; i++) {
            a[i][1] = unhappines[1][i];
        }
        for (int stable=2; stable<=s; stable++) {
            for (int i=stable; i<=maxes[stable]; i++) {
                for (int j=i; j<=maxes[stable]; j++) {
                    int prev = a[i-1][stable-1];
                    a[j][stable] = Math.min(a[j][stable], unhappines[i][j]+prev );
                }
            }
        }
        System.out.println(a[h][s]);
    }

    static class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        FastScanner(Reader in) {
            br = new BufferedReader(in);
        }

        String next() {
            while (st == null || !st.hasMoreTokens()) {
                try {
                    st = new StringTokenizer(br.readLine());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }
    }

}