#include <bits/stdc++.h>
using namespace std;
int tree[2][120000], n, l, r, p[120000], a[120000], i;
long long ans, k, v;
int der(int x) { return lower_bound(p + 1, p + n + 1, x) - p; }
int calc(int o, int x) {
  if (!o) x = n - x + 1;
  int res = 0;
  for (int i = x; i; i -= i & (-i)) res += tree[o][i];
  return res;
}
void add(int o, int x, int flag) {
  if (!o) x = n - x + 1;
  for (int i = x; i <= n; i += i & (-i)) tree[o][i] += flag;
}
int main() {
  scanf("%d%I64d", &n, &k);
  for (i = 1; i <= n; ++i) scanf("%d", &a[i]), p[i] = a[i];
  sort(p + 1, p + n + 1);
  for (i = n; i >= 1; --i) {
    a[i] = der(a[i]);
    v += calc(1, a[i] - 1);
    add(1, a[i], 1);
  }
  r = 1;
  for (l = 1; l <= n; ++l) {
    v += calc(0, a[l] + 1) + calc(1, a[l] - 1);
    add(0, a[l], 1);
    while ((r <= l || v > k) && r <= n) {
      v -= calc(0, a[r] + 1) + calc(1, a[r] - 1);
      add(1, a[r], -1);
      r++;
    }
    ans += n - r + 1;
  }
  printf("%I64d\n", ans);
}
