#include <bits/stdc++.h>
const int MAX_N = 100000;
static inline int lsb(int x) { return x & (-x); }
struct InversionCounter {
  int aib[2][1 + MAX_N];
  void update(int t, int pos, int val) {
    while (pos <= MAX_N) {
      aib[t][pos] += val;
      pos += lsb(pos);
    }
  }
  int query(int t, int pos) {
    int res = 0;
    while (pos > 0) {
      res += aib[t][pos];
      pos -= lsb(pos);
    }
    return res;
  }
} big_aib;
long long inversions;
void my_insert(int t, int val) {
  inversions =
      inversions + big_aib.query(0, MAX_N - val) + big_aib.query(1, val - 1);
  if (t == 0) val = MAX_N - val + 1;
  big_aib.update(t, val, 1);
}
void my_erase(int t, int val) {
  inversions =
      inversions - big_aib.query(0, MAX_N - val) - big_aib.query(1, val - 1);
  if (t == 0) val = MAX_N - val + 1;
  big_aib.update(t, val, -1);
}
int v[1 + MAX_N];
int* pnt[MAX_N];
bool cmp(int* a, int* b) { return *a < *b; }
void normalize(int n) {
  for (int i = 1; i <= n; ++i) pnt[i - 1] = &v[i];
  std::sort(pnt, pnt + n, cmp);
  int last = *pnt[0], j = 1;
  for (int i = 0; i < n; ++i) {
    if (last == *pnt[i])
      *pnt[i] = j;
    else {
      last = *pnt[i];
      *pnt[i] = ++j;
    }
  }
}
int main() {
  int n;
  long long k;
  scanf("%d%lld", &n, &k);
  for (int i = 1; i <= n; ++i) scanf("%d", &v[i]);
  normalize(n);
  for (int i = 1; i <= n - 1; ++i) my_insert(0, v[i]);
  int last = n - 1;
  long long res = 0LL;
  for (int i = n; i >= 2; --i) {
    my_insert(1, v[i]);
    if (last == i) {
      my_erase(0, v[last]);
      last--;
    }
    while (last > 0 && inversions > k) {
      my_erase(0, v[last]);
      --last;
    }
    res = res + last;
  }
  printf("%lld", res);
  return 0;
}
