#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <limits>
#include <unordered_set>

using namespace std;


long long int cost(vector<int>& c, int k, vector<int>& stat, int rem, int p) {
    if(p==c.size()) {
        if(rem > 0)
            return numeric_limits<long long int>::max();    
        return 0;
    }
    if(rem == 0)
        return 0;
    
    long long int res= cost(c,k,stat,rem,p+1);
    
    unordered_set<int> pos;
    for(int i=max(0,p-k); i<min(p+k+1, (int)c.size());++i) {
        if(stat[i] == 1) {
            stat[i] = 0;
            rem--;   
            pos.insert(i);
        }
    }
    
    long long int res1=cost(c,k,stat,rem, p+1);
    if(res1!=numeric_limits<long long int>::max())
        res1+=c[p];
    
    for(auto i : pos) {
        stat[i]=1;
    }

    return min(res, res1);
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
    int b,k;
    cin >> b >> k;
    long long int tot=0;
    vector<int> c(b);
    for(int i=0;i<b;++i) {
        cin >> c[i];
        tot+=c[i];
    }
    
    if(k>0) {
        vector<int> stat(b,1);
        cout << cost(c,k,stat, c.size(),0);
    }
    else
        cout << tot;
    
    return 0;
}