#include <bits/stdc++.h>
using namespace std;
const double eps = 1E-8;
const int dx4[4] = {1, 0, 0, -1};
const int dy4[4] = {0, -1, 1, 0};
const int inf = 0x3f3f3f3f;
const int N = 2E5 + 7;
int tree[2][N];
int a[N], p[N];
int n;
long long k;
int lowbit(int x) { return x & (-x); }
void update(int o, int x, int delta) {
  if (!o) x = n - x + 1;
  for (int i = x; i <= n; i += lowbit(i)) tree[o][i] += delta;
}
int Hash(int x) { return lower_bound(p + 1, p + n + 1, x) - p; }
int Sum(int o, int x) {
  if (!o) x = n - x + 1;
  int res = 0;
  for (int i = x; i >= 1; i -= lowbit(i)) res += tree[o][i];
  return res;
}
int main() {
  cin >> n >> k;
  for (int i = 1; i <= n; i++) cin >> a[i], p[i] = a[i];
  sort(p + 1, p + n + 1);
  long long total = 0;
  for (int i = n; i >= 1; i--) {
    int x = Hash(a[i]);
    a[i] = x;
    total += Sum(1, a[i] - 1);
    update(1, a[i], 1);
  }
  int r = 1;
  long long ans = 0;
  for (int l = 1; l <= n; l++) {
    total += Sum(0, a[l] + 1) + Sum(1, a[l] - 1);
    update(0, a[l], 1);
    while ((r <= l || total > k) && r <= n) {
      total -= Sum(0, a[r] + 1) + Sum(1, a[r] - 1);
      update(1, a[r], -1);
      r++;
    }
    ans += n - r + 1;
  }
  cout << ans << endl;
  return 0;
}
