#pragma comment(linker, "/STACK:10240000,10240000")

 #include <iostream>

 #include <cstdio>

 #include <algorithm>

 #include <cstdlib>

 #include <cstring>

 #include <map>

 #include <queue>

 #include <deque>

 #include <cmath>

 #include <vector>

 #include <ctime>

 #include <cctype>

 #include <set>

 using namespace std;

 #define mem0(a) memset(a, 0, sizeof(a))

 #define lson l, m, rt << 1

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

 #define define_m int m = (l + r) >> 1

 #define Rep(a, b) for(int a = 0; a < b; a++)

 #define lowbit(x) ((x) & (-(x)))

 #define constructInt4(name, a, b, c, d) name(int a = 0, int b = 0, int c = 0, int d = 0): a(a), b(b), c(c), d(d) {}

 #define constructInt3(name, a, b, c) name(int a = 0, int b = 0, int c = 0): a(a), b(b), c(c) {}

 #define constructInt2(name, a, b) name(int a = 0, int b = 0): a(a), b(b) {}

 typedef double db;

 typedef long long LL;

 typedef pair<int, int> pii;

 typedef multiset<int> msi;

 typedef multiset<int>::iterator msii;

 typedef set<int> si;

 typedef set<int>::iterator sii;

 typedef vector<int> vi;

 const int dx[] = {, , -, , , , -, -};

 const int dy[] = {, -, , , -, , , -};

 const int maxn = 1e5 + ;

 const int maxm = 1e5 + ;

 const int maxv = 1e7 + ;

 const int MD = 1e9 +;

 const int INF = 1e9 + ;

 const double PI = acos(-1.0);

 const double eps = 1e-;

 int tmp[maxn], a[maxn];

 LL merge(int l, int m, int r) {

     int p = m + , t = l;

     LL res = ;

     for (int i = l; i <= m; i++) {

         while (p <= r && a[i] > a[p]) {

             tmp[t++] = a[p++];

         }

         res += p - m - ;

         tmp[t++] = a[i];

     }

     for (int i = l; i < p; i++) a[i] = tmp[i];

     return res;

 }

 LL merge_sort(int l, int r) {

     if (l == r) return ;

     define_m;

     return merge_sort(l, m) + merge_sort(m + , r) + merge(l, m, r);

 }

 int main() {

     //freopen("in.txt", "r", stdin);

     int n;

     LL k;

     while (cin >> n >> k) {

         for (int i = ; i < n; i++) {

             scanf("%d", a + i);

         }

         LL ans = merge_sort(, n - ) - k;

         ans = max(ans, 0LL);

         cout << ans << endl;

     }

     return ;

 }