#include <bits/stdc++.h>
using namespace std;
const int N = 2e5 + 3;
int n, m, i, j, l, r, d, u, ii, jj, h[N];
long long first[N][3], k, t, hh[N], x, y, z, s;
map<int, int> MP;
long long f(int x, int d) {
  long long t = 0;
  for (; x; x -= x & -x) t += first[x][d];
  return t;
}
void up(int x, int d, int k) {
  for (; x and x <= s; x += x & -x) first[x][d] += k;
}
int main() {
  cin >> n >> k;
  for (i = 1; i <= n; i++) {
    scanf("%d", h + i);
    hh[i] = h[i];
  }
  sort(hh + 1, hh + 1 + n);
  for (i = 1; i <= n; i++)
    if (hh[i] != hh[i - 1]) MP[hh[i]] = ++s;
  for (i = n; i; i--) {
    hh[i] = hh[i + 1] + f(MP[h[i]] - 1, 0);
    up(MP[h[i]], 0, 1);
  }
  r = 1;
  for (i = 1; i < n; i++) {
    up(MP[h[i]], 1, 1);
    while (1) {
      x = hh[1] - y - z;
      if (i == r)
        r++;
      else if (x <= k) {
        if (r <= n) t += n - r + 1;
        if (r - i > 1) {
          y -= hh[i + 1] - hh[i + 2] - f(MP[h[i + 1]] - 1, 2);
          z -= f(s, 1) - f(MP[h[i + 1]], 1);
          up(MP[h[i + 1]], 2, -1);
        }
        x = hh[1] - y - z;
        break;
      } else {
        y += hh[r] - hh[r + 1];
        z += f(s, 1) - f(MP[h[r]], 1);
        up(MP[h[r]], 2, 1);
        r++;
        x = hh[1] - y - z;
      }
    }
  }
  cout << t << '\n';
}
