#include <bits/stdc++.h>
using namespace std;
int c[2][100010], n, cnt, a[100010], b[100010];
long long k, ans, sum;
int query(int tmp, int x) {
  int sum = 0;
  for (; x; x -= (x & (-x))) sum += c[tmp][x];
  return sum;
}
void add(int tmp, int x, int y) {
  for (; x <= cnt; x += (x & (-x))) c[tmp][x] += y;
}
int main() {
  scanf("%d %lld", &n, &k);
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]), b[i] = a[i];
  sort(b + 1, b + n + 1);
  cnt = unique(b + 1, b + n + 1) - b - 1;
  for (int i = 1; i <= n; i++) a[i] = lower_bound(b + 1, b + cnt + 1, a[i]) - b;
  for (int i = 1; i <= n; i++) {
    sum += i - 1 - query(0, a[i]);
    add(0, a[i], 1);
  }
  int r = 1;
  for (int i = 1; i < n; i++) {
    sum += query(1, cnt) - query(1, a[i]) + query(0, a[i] - 1);
    add(1, a[i], 1);
    while (r <= i) {
      sum -= query(1, cnt) - query(1, a[r]) + query(0, a[r] - 1);
      add(0, a[r], -1);
      r++;
    }
    while (r <= n && sum > k) {
      sum -= query(1, cnt) - query(1, a[r]) + query(0, a[r] - 1);
      add(0, a[r], -1);
      r++;
    }
    ans += n + 1 - r;
  }
  printf("%lld", ans);
}
