# include <bits/stdc++.h>

using namespace std;

#define pii pair<int, int>
#define pll pair<ll, ll>

#define pb push_back
#define eb emplace_back
#define mp make_pair

#define fi first
#define se second

#define y0 asjdlksajldjals
#define y1 ajsldjalksdkjlk

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;

const int inf = (int)1e9 + 7;
const int maxn = (int)6e5 + 7;
const int lmaxn = (int)6e6 + 7;
const ll linf = (ll)1e16 + 7;

const ld eps = ld(1e-11);

const ll dx[] = {-1, 0, 0, 1};
const ll dy[] = {0, -1, 1, 0};

ll gcd(ll a, ll b){
    while(b) a %= b, swap(a, b);
    return a | b;
}

ll lcm(ll a, ll b){
    return a * b / gcd(a, b);
}

ll n, k;
ll a[1001];
ll d[1001][1001];

ll Calc(ll l, ll r){
    if(l > r) return 0;
    if(d[l][r] != -1)
        return d[l][r];
    if(l == r)
        return a[l];
    d[l][r] = linf;
    for(ll j = l; j <= r; ++j)
        d[l][r] = min(d[l][r], Calc(l, j - k - 1) + Calc(j + k + 1, r) + a[j]);
    return d[l][r];
}

int main(){
    scanf("%lld %lld", &n, &k);
    for(ll i = 1; i <= n; ++i)
        scanf("%lld", &a[i]);
    for(ll i = 1; i <= n; ++i){
        for(ll j = i; j <= n; ++j)
            d[i][j] = -1;
    }
    printf("%lld", Calc(1, n));
    return 0;
}