#include <bits/stdc++.h>
using namespace std;
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
template<class T> using oset =
tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define ll long long
#define ld long double
#define ar array
#define vi vector<int>
#define vii vector<vector<int>>
#define pii pair<int, int>
#define pb push_back
#define all(x) x.begin(), x.end()
#define f first
#define s second
const int MOD = 1e9+7;
const int inf = 1e9;
const ll linf = 1e18;
const int d4i[4]={-1, 0, 1, 0}, d4j[4]={0, 1, 0, -1};
const int d8i[8]={-1, -1, 0, 1, 1, 1, 0, -1}, d8j[8]={0, 1, 1, 1, 0, -1, -1, -1};
// -------------------------------------------------- Main Code --------------------------------------------------
int lis(vi &arr) {
vi dp;
for (int i = 0; i < arr.size(); i++) {
int x = upper_bound(all(dp), arr[i]) - dp.begin();
if (x == dp.size()) dp.pb(arr[i]);
else dp[x] = arr[i];
}
return dp.size();
}
void sol() {
int n, m; cin >> n >> m;
int arr[n];
for (int i = 0; i < n; i++) cin >> arr[i];
vi a;
for (int i = 1; i <= n; i++) {
if (m*i - arr[i-1] >= 0) {
a.pb(m*i - arr[i-1]);
}
}
cout << n-lis(a) << endl;
}
int main () {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int t = 1;
// cin >> t;
while (t--) {
sol();
}
return 0;
}
