#include<iostream>
#include<string>
#include<queue>
#include<vector>
#include<cassert>
#include<random>
#include<set>
#include<map>
#include<cassert>
#include<unordered_map>
#include<bitset>
#include<numeric>
#include<algorithm>
using namespace std;
using ll = long long;
const int inf=1<<30;
const ll INF=1LL<<62;
typedef pair<int,ll> P;
typedef pair<int,P> PP; 
const ll MOD=998244353;


ll op(ll x, ll y){
    //(x,y)を比較する任意の演算子.今回はmaxとした
    return min(x,y);
}

ll e(){
    //initialize value
    return INF;
}


template<class Type,
    Type (*op)(Type,Type),
    Type (*e)()
    > class segment_tree{
    
    public:
        
        std::vector<Type> dat;
        int n=1;
        segment_tree(int n_){    
            while(n < n_){
                n*=2;
            }
            dat = std::vector<Type>(2*n-1,e());// 0,1,2,...,2*n-1,2*n-2
        }

        ~segment_tree(){
            std::vector<Type>().swap(dat);
        }

        void set(int k,Type a){
            update(k,a);
        }


        void update(int k,Type a){
            k+=n-1;
            dat[k] = a;
            while(k>0){
                k = (k-1)/2;
                dat[k]=op(dat[2*k+1],dat[2*k+2]);
            }
        }

        //[a,b)
        Type query(int a,int b,int k,int l,int r){
            if(r<=a || b<=l) return e();
            if(a<=l && r<=b) return dat[k];
            else{

                Type vl = query(a,b,2*k+1,l,(l+r)/2);
                Type vr = query(a,b,2*k+2,(l+r)/2,r);
                return op(vl,vr);
            }
        }

        //[a,b)の範囲でのmax
        Type query(int a,int b){
            return query(a,b,0,0,n);
        }

        Type operator[](int index){
            
            return get(index);
        }

        Type get(int index){
            index += n-1;
            return dat[index];
        }

        void add(int index,Type val){
            update(index,op(get(index),val));
        }
};


int main(){
    int N,K;
    cin>>N>>K;
    vector<ll> A(N+2);
    ll totA=0;
    for(int i=1;i<=N;i++){
        cin>>A[i];
        totA+=A[i];
    }
    vector<ll> dp(N+2);
    segment_tree<ll,op,e> seg(N+2);
    dp[0]=0;
    seg.update(0,0);
    for(int i=1;i<=N+1;i++){
        //[i-K,i)
        //A[i]を必ずとる
        dp[i]=seg.query(max(0,i-K),i)+A[i];
        seg.update(i,dp[i]);
    }

    // for(int i=1;i<=N+1;i++){
    //     cout<<"dp["<<i<<"]="<<dp[i]<<endl;
    // }

    // cout<<"totA="<<totA<<endl;

    ll ans=totA-dp[N+1];
    cout<<ans<<endl;



    
}