#include <iostream>
#include <cstdio>
#include <deque>
#include <vector>

using namespace std;

deque <int> q;
int v[5000007];
int n , k , sum;

int main()
{
    freopen ("deque.in" , "r" , stdin );
    freopen ("deque.out" , "w" , stdout );
    scanf ("%d%d" , &n , &k );
    for ( int i = 1; i <= n ; ++i )
        scanf ("%d" , &v[i]);
    for ( int i = 1; i <= n ; ++i )
    {
        while ( !q.empty ( ) and v [ i ] <= v [ q.back ( ) ] )
            q.pop_back ( ) ;
        if (q.front==i-k)front++;
        if (i>=k)sum=sum+a[q.front];
    }
    printf ("%d" , &sum ) ;
    return 0;
}