#include <bits/stdc++.h>
using namespace std;
struct _ {
  _() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
  }
} _;
const long long base = 311, mod = 1e9 + 7, N = 3e5 + 11, inf = INT_MAX;
long long n, k, r = 1, mx = 0, ans = 0, inverse_count = 0, a[N], tree_left[N],
                tree_right[N];
map<long long, long long> m;
void update_left(long long k, long long x) {
  while (k <= mx) tree_left[k] += x, k += k & -k;
}
void update_right(long long k, long long x) {
  while (k <= mx) tree_right[k] += x, k += k & -k;
}
long long sum_left(long long k) {
  long long sum = 0;
  while (k) sum += tree_left[k], k -= k & -k;
  return sum;
}
long long sum_right(long long k) {
  long long sum = 0;
  while (k) sum += tree_right[k], k -= k & -k;
  return sum;
}
signed main() {
  cin >> n >> k;
  for (long long i = 1; i <= n; i++) {
    cin >> a[i];
    m[a[i]] = 1;
  }
  for (auto &x : m) {
    x.second = ++mx;
  }
  for (long long i = 1; i <= n; i++) {
    a[i] = m[a[i]];
  }
  for (long long i = n; i >= 1; i--) {
    inverse_count += sum_right(a[i] - 1);
    update_right(a[i], 1);
  }
  for (long long l = 1; l <= n; l++) {
    inverse_count += (sum_left(mx) - sum_left(a[l])) + sum_right(a[l] - 1);
    update_left(a[l], 1);
    while ((r <= l && r <= n) || (inverse_count > k && r <= n)) {
      inverse_count -= (sum_left(mx) - sum_left(a[r])) + sum_right(a[r] - 1);
      update_right(a[r], -1);
      r++;
    }
    ans += n - r + 1;
  }
  cout << ans;
}
