#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic pop
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

constexpr long long INF = 1002003004005006007;
ll op(ll x, ll y) { return min(x, y); }
ll e() { return INF; }

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, k;
  cin >> n >> k;
  VI a(n + 1);
  rep(i, n) cin >> a[i + 1];
  ll ans = accumulate(all(a), 0LL);
  segtree<ll, op, e> seg(n + 1);
  seg.set(0, 0);
  for(int i = 1; i <= n; i++) {
    ll v = seg.prod(max(0, i - k), i) + a[i];
    seg.set(i, v);
  }
  ans -= seg.prod(n + 1 - k, n + 1);
  cout << ans << '\n';
}