#include <bits/stdc++.h>
#pragma comment(linker, "/STACK:66777216")
using namespace std;
int a, b, c, d, i, j, n, m, k;
long long lim;
int mas[100002], num[100002];
int fen[100002], fen2[100002];
long long pr[100002], suf[100002];
inline void upd(int first, int val) {
  for (; first < k; first |= first + 1) fen[first] += val;
}
inline int sum(int first) {
  int ans = 0;
  for (; first >= 0; first = (first & (first + 1)) - 1) ans += fen[first];
  return ans;
}
inline int sum(int l, int r) {
  if (l > r) return 0;
  return sum(r) - sum(l - 1);
}
inline void upd2(int first, int val) {
  for (; first < k; first |= first + 1) fen2[first] += val;
}
inline int sum2(int first) {
  int ans = 0;
  for (; first >= 0; first = (first & (first + 1)) - 1) ans += fen2[first];
  return ans;
}
inline int sum2(int l, int r) {
  if (l > r) return 0;
  return sum2(r) - sum2(l - 1);
}
int main() {
  scanf("%d%I64d", &n, &lim);
  for (int _n((n)-1), i(0); i <= _n; i++)
    scanf("%d", &mas[i]), num[k++] = mas[i];
  sort(num, num + k);
  k = unique(num, num + k) - num;
  for (int _n((n)-1), i(0); i <= _n; i++)
    mas[i] = lower_bound(num, num + k, mas[i]) - num;
  long long cur = 0;
  for (int _n((n)-1), i(0); i <= _n; i++) {
    cur += sum(mas[i] + 1, k - 1);
    pr[i] = cur;
    upd(mas[i], 1);
  }
  memset((fen), 0, sizeof(fen));
  cur = 0;
  for (int i = (n - 1), _b = (0); i >= _b; i--) {
    cur += sum(mas[i] - 1);
    suf[i] = cur;
    upd(mas[i], 1);
  }
  memset((fen), 0, sizeof(fen));
  a = n - 1;
  cur = 0;
  long long ans = 0;
  for (int _n((n)-1), i(0); i <= _n; i++) {
    upd(mas[i], 1);
    cur += sum2(mas[i] - 1);
    while (a > i) {
      long long diff = sum(mas[a] + 1, k - 1);
      long long now = pr[i] + suf[a] + diff + cur;
      if (now > lim) break;
      cur += diff;
      upd2(mas[a], 1);
      --a;
    }
    while (a < i) {
      long long diff = sum(mas[a + 1] + 1, k - 1);
      cur -= diff;
      upd2(mas[a + 1], -1);
      ++a;
    }
    while (a < n - 1) {
      long long now = pr[i] + suf[a + 1] + cur;
      if (now <= lim) break;
      long long diff = sum(mas[a + 1] + 1, k - 1);
      cur -= diff;
      upd2(mas[a + 1], -1);
      ++a;
    }
    ans += n - 1 - a;
  }
  cout << ans << endl;
}
