#include <bits/stdc++.h>
using namespace std;
long long na, nb, k, a[100010], b[100010], i, j;
long long big[100010], sml[100010];
void I(long long *dat, long long x, long long d, long long v) {
  while (x > 0 && x <= nb) dat[x] += v, x += d * (x & -x);
}
long long Q(long long *dat, long long x, long long d) {
  long long ret = 0;
  while (x > 0 && x <= nb) ret += dat[x], x += d * (x & -x);
  return ret;
}
int main() {
  cin >> na >> k;
  for (i = 0; i < na; i++) cin >> a[i], b[i] = a[i];
  nb = unique(b, b + na) - b;
  sort(b, b + nb);
  for (i = 0; i < na; i++) a[i] = lower_bound(b, b + nb, a[i]) - b + 1;
  long long cnt = 0;
  for (i = na - 1; i >= 0; i--) {
    cnt += Q(sml, a[i] - 1, -1);
    I(sml, a[i], 1, 1);
  }
  I(sml, a[0], 1, -1);
  I(big, a[0], -1, 1);
  long long ans = 0;
  i = 0, j = 1;
  while (i < na && j < na) {
    while (i == j || cnt > k && j < na) {
      cnt -= Q(big, a[j] + 1, 1) + Q(sml, a[j] - 1, -1);
      I(sml, a[j++], 1, -1);
    }
    ans += na - j;
    cnt += Q(big, a[++i] + 1, 1) + Q(sml, a[i] - 1, -1);
    I(big, a[i], -1, 1);
  }
  cout << ans << endl;
}
