The Little Elephant has array a, consisting of n positive integers, indexed from 1 to n. Let's denote the number with index i as ai.

The Little Elephant wants to count, how many pairs of integers l and r are there, such that 1 ≤ l < r ≤ n and sequence b = a1a2... alarar + 1... an has no more than k inversions. 

An inversion in sequence b is a pair of elements of the sequence b, that change their relative order after a stable sorting of the sequence. In other words, an inversion is a pair of integers i and j, such that 1 ≤ i < j ≤ |b| and bi > bj, where |b| is the length of sequence b, and bj is its j-th element.

Help the Little Elephant and count the number of the described pairs.

Input

The first line contains two integers n and k (2 ≤ n ≤ 105, 0 ≤ k ≤ 1018) — the size of array a and the maximum allowed number of inversions respectively. The next line contains n positive integers, separated by single spaces, a1, a2, ..., an (1 ≤ ai ≤ 109) — elements of array a.

Please, do not use the %lld specifier to read or write 64-bit integers in С++. It is preferred to use cin, cout streams or the %I64d specifier.

Output

In a single line print a single number — the answer to the problem.

Examples

Input

3 1
1 3 2


Output

3


Input

5 2
1 3 2 1 7


Output

6
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.Comparator;
import java.util.StringTokenizer;

public class LittlElephantAndInversions {
    public void compress(int[] a) {
        Comparator<int[]> C = new Comparator<int[]>() {
            public int compare(int[] o1, int[] o2) {
                return o1[1] - o2[1];
            }
        };
        int[][] arr = new int[a.length][2];
        for (int i = 0; i < arr.length; i++) {
            arr[i][0] = i;
            arr[i][1] = a[i];
        }
        Arrays.sort(arr, C);
        int last = 1;
        a[arr[0][0]] = last;
        for (int i = 1; i < arr.length; i++) {
            if (arr[i][1] == arr[i - 1][1])
                a[arr[i][0]] = last;
            else
                a[arr[i][0]] = ++last;
        }
    }

    class BIT {
        int[] bit;

        public BIT(int n) {
            bit = new int[n + 1];
        }

        public int query(int i) {
            int sum = 0;
            for (i = i + 1; i > 0; i -= i & -i)
                sum += bit[i];
            return sum;
        }

        public void add(int i, int val) {
            for (i = i + 1; i < bit.length; i += i & -i)
                bit[i] += val;
        }

        public int query(int l, int r) {
            return query(r) - query(l - 1);
        }
    }

    public void run() throws Exception {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer strtok = new StringTokenizer(in.readLine());
        int n = Integer.parseInt(strtok.nextToken());
        long k = Long.parseLong(strtok.nextToken());
        int[] a = new int[n];
        strtok = new StringTokenizer(in.readLine());
        for (int i = 0; i < n; i++)
            a[i] = Integer.parseInt(strtok.nextToken());
        compress(a);
        BIT left = new BIT(n + 2);
        BIT right = new BIT(n + 2);
        long inversions = 0;
        long pairs = 0;
        for (int i = n - 1; i >= 1; i--) {
            right.add(a[i], 1);
            inversions += right.query(a[i] - 1);
        }
        int r = 1;
        for (int i = 0; i < n - 1; i++) {
            left.add(a[i], 1);
            inversions += left.query(a[i] + 1, n + 1) + right.query(a[i] - 1);
            while (inversions > k && r < n) {
                right.add(a[r], -1);
                inversions -= right.query(a[r] - 1)
                        + left.query(a[r] + 1, n + 1);
                r++;
            }
            if (inversions > k)
                break;
            pairs += n - r;
            if (r == i + 1 && r < n) {
                right.add(a[r], -1);
                inversions -= right.query(a[r] - 1)
                        + left.query(a[r] + 1, n + 1);
                r++;
            }
        }
        System.out.println(pairs);
    }

    public static void main(String[] args) throws Exception {
        (new LittlElephantAndInversions()).run();
    }
}
