/************************************************

* Author        :Running_Time

* Created Time  :2015/9/12 星期六 20:31:07

* File Name     :J.cpp

 ************************************************/

#include <cstdio>

#include <algorithm>

#include <iostream>

#include <sstream>

#include <cstring>

#include <cmath>

#include <string>

#include <vector>

#include <queue>

#include <deque>

#include <stack>

#include <list>

#include <map>

#include <set>

#include <bitset>

#include <cstdlib>

#include <ctime>

using namespace std;

#define lson l, mid, rt << 1

#define rson mid + 1, r, rt << 1 | 1

typedef long long ll;

const int N = 1e5 + 10;

const int INF = 0x3f3f3f3f;

const int MOD = 1e9 + 7;

int a[N], L[N/2], R[N/2];

ll cnt;

void Merge(int *a, int p, int q, int r)   {

    int n1 = q - p + 1, n2 = r - q;

    for (int i=1; i<=n1; ++i)   L[i] = a[p+i-1];

    for (int i=1; i<=n2; ++i)   R[i] = a[q+i];

    L[n1+1] = R[n2+1] = INF;

    for (int i=1, j=1, k=p; k<=r; ++k)  {

        if (L[i] <= R[j])    a[k] = L[i++];

        else    {

            a[k] = R[j++];  cnt += n1 - i + 1;

        }

    }

}

void Merge_Sort(int *a, int p, int r)   {

    if (p < r)  {

        int q = (p + r) >> 1;

        Merge_Sort (a, p, q);

        Merge_Sort (a, q+1, r);

        Merge (a, p, q, r);

    }

}

int main(void)    {

    int n;  ll k;

    while (scanf ("%d%I64d", &n, &k) == 2) {

        for (int i=1; i<=n; ++i)    scanf ("%d", &a[i]);

        cnt = 0;

        Merge_Sort (a, 1, n);

        printf ("%I64d\n", max (cnt - k, (ll) 0));

    }

    return 0;

}