// XD XD
#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define el cout << "\n";
using namespace std;
using ll = long long;
const int MAXN = 1e6 + 7;
const int MOD = 1e9 + 7;
const int INF = 1e9 + 7;
const ll LLINF = 1e18 + 7;
template <typename T>
bool ckmin(T& a, T b) {
return a > b ? a = b, true : false;
}
template <typename T>
bool ckmax(T& a, T b) {
return a < b ? a = b, true : false;
}
int n, k;
pair<int, int> a[MAXN];
void solve(int id) {
// cout << "Case " << id << ": ";
cin >> n >> k;
for (int i = 1; i <= n; i++) {
cin >> a[i].first;
a[i].second = i;
}
sort(a + 1, a + n + 1);
for (int i = 1; i <= n; i++) {
a[i].first = (i - 1) / k + 1;
swap(a[i].first, a[i].second);
}
sort(a + 1, a + n + 1);
multiset<int> ms;
for (int i = 1; i <= n; i++) {
auto it = ms.upper_bound(a[i].second);
if (it != ms.end()) {
ms.erase(it);
}
ms.insert(a[i].second);
}
cout << n - ms.size() << "\n";
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
int T = 1;
// cin >> T;
for (int i = 1; i <= T; i++) {
solve(i);
}
return 0;
}
