#include <bits/stdc++.h>
#define endl '\n'

using namespace std;

const int N = 10007;
const int K = 1007;
const long long INF = (1e18) + 7;

int tests,current_case;
int n,k,a[N];
bool used[N][K];
long long state[N][K];
long long ans;

void message(int current_case) {
    //cerr<<"Case "<<current_case<<" solved!"<<endl;
    fprintf(stderr, "Case %d solved!\n", current_case);
}

long long recurse(int pos, int last) {
    if(pos>n) {
        if(n-last<=k) return 0;
        else return INF;
    }
    if(used[pos][last]) return state[pos][last];
    long long ans=recurse(pos+1,pos)+a[pos];
    if(pos==n) {
        if(n-last<=k) ans=min(ans,recurse(pos+1,last));
    }
    else {
        if(pos+1-k<=last+k) ans=min(ans,recurse(pos+1,last));
    }
    used[pos][last]=true;
    state[pos][last]=ans;
    return ans;
}

int main() {
    //ios_base::sync_with_stdio(false);
    //cin.tie(NULL);
    int i;

    tests=1;
    //scanf("%d", &tests);
    for(current_case=1;current_case<=tests;current_case++) {
        scanf("%d %d", &n, &k);
        for(i=1;i<=n;i++) scanf("%d", &a[i]);
        if(k>=n-1) {
            ans=INF;
            for(i=1;i<=n;i++) ans=min(ans,(long long)(a[i]));
            printf("%lld\n", ans);
            goto STOP;
        }
        memset(used,0,sizeof(used));
        ans=INF;
        for(i=1;i<=k+1 && i<=n;i++) ans=min(ans,recurse(i+1,i)+a[i]);
        //ans=min(ans,recurse(1,0));
        printf("%lld\n", ans);
        STOP:
        message(current_case);
    }

    return 0;
}