#include <bitset>
#include <iostream>
#include <vector>
#include <math.h>
#include <set>
#include <map>

using namespace std;

struct UnionFind {
  int n;
  vector<int> parent, siz;
 
  UnionFind(int n) : n(n) {
    parent.resize(n);
    siz.resize(n);
 
    for (int i = 0; i < n; ++i) {
      parent[i] = i;
      siz[i] = 1;
    }
  }
 
  int root(int x) {
    if (parent[x] == x) return x;
    return parent[x] = root(parent[x]);
  }
 
  bool unite(int x, int y) {
    x = root(x);
    y = root(y);
 
    if (x == y) return false;
 
    if (siz[x] < siz[y]) swap(x, y);
    parent[y] = x;
    siz[x] += siz[y];
 
    return true;
  }
 
  int same(int x, int y) {
    return root(x) == root(y);
  }
 
  int size(int x) {
    return siz[root(x)];
  }
};

using ll = long long;

struct RminQ {
  const ll INFLL = 1e18;
  int m;
  vector<long long> dat;
 
  RminQ(int n) {
    m = 1;
    while (m < n) m *= 2;
 
    dat.assign(2 * m - 1, INFLL);
  }
 
  void update(int i, long long x) {
    i += m - 1;
    dat[i] = x;
 
    while (i) {
      i = (i - 1) / 2;
      dat[i] = min(dat[i * 2 + 1], dat[i * 2 + 2]);
    }
  }
 
  // [a, b)
  long long query(int a, int b, int k, int l, int r) {
    if (l >= b || r <= a) return INFLL;
    if (a <= l && r <= b) return dat[k];
    
    long long vl = query(a, b, k * 2 + 1, l, (l + r) / 2);
    long long vr = query(a, b, k * 2 + 2, (l + r) / 2, r);
 
    return min(vl, vr);
  }
 
  long long query_sub(int a, int b) {
    return query(a, b, 0, 0, m);
  }
};

int main(void) {
  int n, k;
  cin >> n >> k;

  vector<int> a(n + 2, 0);
  for (int i = 1; i <= n; ++i) cin >> a[i];

  RminQ seg(n + 5);
  seg.update(0, 0);

  for (int i = 1; i <= n + 1; ++i) {
    int mn = seg.query_sub(i - k, i);
    seg.update(i, mn + a[i]);
  }

  long long ans = 0;
  for (int i = 0; i < n + 2; ++i) ans += a[i];

  ans -= seg.query_sub(n+1, n+2);

  cout << ans << endl;
  return 0;
}