#include <bits/stdc++.h>
using namespace std;

#define REP(i, a, b) for (int i = a; i <= b; i++)
#define FOR(i, n) for (int i = 0; i < n; i++)
#define foreach(it, ar) for ( typeof(ar.begin()) it = ar.begin(); it != ar.end(); it++ )
#define fill(ar, val) memset(ar, val, sizeof(ar))
#define PI 3.1415926535897932385
#define uint64 unsigned long long
#define Int long long
#define int64 long long
#define all(ar) ar.begin(), ar.end()
#define pb push_back
#define ff first
#define ss second
#define bit(n) (1<<(n))
#define Last(i) ( (i) & (-i) )
#define sq(x) ((x) * (x))
#define INF INT_MAX
#define mp make_pair
#define MAXN 1001
#define LOGMAXN 19
int A[ MAXN ] ;
int n, k  ;
int dp[ MAXN ][ MAXN ];
int rec( int l ,  int r   )
  {
      int cost = INT_MAX ;
      if(  r < 0 ) return 0 ;
      if(  l >= n ) return 0 ;
      if(  r < l ) return 0 ;
      if(  l < 0 ) return 0 ;
      if(  r >= n ) return 0;

      //cout << l << " " << r <<endl;
      //cin >> n ;
      if(  dp[l][r] != -1 )return dp[l][r] ;

      for( int i = l ; i <=  r ; i ++  )
         cost = min( cost , A[i] + rec( l , i - k - 1 ) + rec( i + k + 1 ,  r ) ) ;

      dp[ l ][ r ]  =  cost ;
      return  cost ;
  }
 int main ( )
 {

      cin >> n >> k ;
      FOR( i , n )cin >> A[i] ;
      FOR( i , MAXN) FOR( j , MAXN ) dp[i][j] = -1 ;
      cout<< rec(  0  ,  n-1 ) <<  endl ; ;

 }