#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(), x.end()
int lds(vector<int> x){
int n = (int) x.size();
vector<int> ord, seg((n + 5) * 2, 0);
for(int i = 0; i < n; ++i){
ord.push_back(x[i]);
}
sort(all(ord));
ord.erase(unique(all(ord)), ord.end());
auto pos = [&](int x) -> int {
return lower_bound(all(ord), x) - ord.begin();
};
auto update = [&](int idx, int val) -> void {
idx += n;
seg[idx] = max(seg[idx], val);
while(idx > 1){
idx >>= 1;
seg[idx] = max(seg[idx << 1], seg[idx << 1 | 1]);
}
};
auto query = [&](int l, int r) -> int {
if(l > r) return 0;
l += n, r += n;
int ans = 0;
while(l <= r){
if(l & 1) ans = max(ans, seg[l ++]);
if(r & 1 ^ 1) ans = max(ans, seg[r --]);
l >>= 1, r >>= 1;
}
return ans;
};
for(auto it : x){
int i = pos(it);
update(i, query(i, n - 1) + 1);
}
return *max_element(all(seg));
}
signed main(){
ios::sync_with_stdio(0);
cin.tie(nullptr); cout.tie(nullptr);
int n, m;
cin >> n >> m;
vector<int> ar(n + 1), dp(n + 5, 1);
for(int i = 1; i <= n; ++i){
cin >> ar[i];
ar[i] -= m * i;
}
for(int i = 1; i <= n; ++i){
for(int j = i - 1; j >= 1; --j){
if(ar[j] >= ar[i]) dp[i] = max(dp[i], dp[j] + 1);
}
}
cout << n - *max_element(all(dp)) << "\n";
return 0;
}
