#include <bits/stdc++.h>
using namespace std;
int n,k,i,ma,df,v[5000010],mi,s;
deque<int>dm;
int main()
{
    freopen("deque.in","r",stdin);
    ofstream g ("deque.out");
    scanf("%d%d",&n,&k);
    for(i=1; i<=n; ++i)
        scanf("%d",&v[i]);
        mi=10000001;
    for(i=1; i<=n; ++i)
    {
        while(!dm.empty()&&v[i]<v[dm.front()])dm.pop_front();
        dm.push_back(i);
        if(i-dm.front()>k){dm.pop_front();s+=mi;mi=10000001;}
        if(v[dm.front()]<mi)mi=v[dm.front()];
    }
    g<<s;
    return 0;
}