#include <fstream>  
#include <deque>
#define NMAX 5000010  
using namespace std;
int V[NMAX], N, K;  
deque <int> deq;
long long S;  
int main()  
{  
    ifstream f ("deque.in");  
    ofstream g ("deque.out");  
    int i,nr,x;   
    f>>N>>K;
    for(i=1;i<=N;i++)  f>>V[i];  
    for(i=1;i<=N;i++)
    {  
         nr=1;            
         while(V[i]>deq.front()) deq.pop_front();
         deq.push_back(V[i]),nr++;           
         if(nr==K) x=deq.back(),deq.pop_back(), nr--;
         S+=x;
    }  
    g<<S;  
    return 0;  
}