#define _CRT_SECURE_NO_WARNINGS
#include "bits/stdc++.h"
using namespace std;
#define all(a) a.begin(), a.end()
const int mxn = 1e5 + 3;
struct BIT {
  int tree[mxn] = {};
  void upd(int r, int x) {
    for (; r < mxn; r += r & -r) {
      tree[r] += x;
    }
  }
  int get(int r) {
    int res = 0;
    for (; r > 0; r -= r & -r) {
      res += tree[r];
    }
    return res;
  }
  int sum(int l, int r) {
    return get(r) - get(l - 1);
  }
  int kth(int k, int s) {
    swap(k, s);
    k += get(s - 1);
    s = 0;
    for (int i = 20; i >= 0; i--) {
      if (s + (1ll << i) < mxn && tree[s + (1ll << i)] < k) {
        s += (1ll << i);
        k -= tree[s];
      }
    }
    return s + 1;
  }
};

signed main() {
#ifdef _DEBUG
  freopen("input.txt", "r", stdin);
  freopen("output.txt", "w", stdout);
#endif
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  int n, k; cin >> n >> k;
  vector<pair<int, int>> a(n);
  vector<int> next(n + 3), last(n + 3);
  BIT T;
  for (int i = 0; i < n; i++) {
    cin >> a[i].first;
    a[i].second = i + 1;
    T.upd(i + 1, 1);
    next[i + 1] = i + 2;
    last[i + 1] = i;
  }
  next[0] = 1;
  last[n + 1] = n;
  next[n + 1] = n + 2;
  last[n + 2] = n + 1;
  T.upd(n + 1, 1);
  T.upd(n + 2, 1);
  long long ans = 0;
  sort(all(a));
  for (int i = 0; i <= n - k; i++) {
    int sub_k = k;
    int cnt_bad = T.sum(1, a[i].second);
    int left_1 = 0, left_2 = 1, right_1 = a[i].second, right_2 = T.kth(a[i].second + 1, 1);
    if (cnt_bad <= sub_k) {
      sub_k -= cnt_bad;
      left_2 = T.kth(1, 1);
      if (sub_k) {
        right_1 = T.kth(a[i].second + 1, sub_k);
        right_2 = T.kth(right_1 + 1, 1);
      }
    }
    else {
      left_1 = T.kth(1, cnt_bad - sub_k);
      left_2 = T.kth(left_1 + 1, 1);
    }
    while (1) {
      long long segs = (long long)(left_2 - left_1) * (long long)(right_2 - right_1);
      ans += (segs * a[i].first);
      if (right_2 == n + 1) {
        break;
      }
      swap(right_1, right_2);
      right_2 = next[right_1];
      swap(left_1, left_2);
      if (left_1 == a[i].second) {
        break;
      }
      left_2 = next[left_1];
    }
    T.upd(a[i].second, -1);
    next[last[a[i].second]] = next[a[i].second];
    last[next[a[i].second]] = last[a[i].second];
  }
  cout << ans;
}