#include <iostream>
#include <stack>
#include <vector>
using namespace std;
int max_non_dec_subseq(const vector<int> &v) {
int n = v.size();
stack<int> s;
int dp[n];
for (int i=0; i<n; i++) {
while (!s.empty() && v[s.top()] > v[i]) {
s.pop();
}
if (s.empty()) {
dp[i] = 1;
}
else {
dp[i] = dp[s.top()] + 1;
}
s.push(i);
}
int ans = 0;
for (int i=0; i<n; i++) {
ans = max(ans, dp[i]);
}
return ans;
}
int main() {
int n, m; cin >> n >> m;
int a[n+1];
a[0] = 0;
for (int i=1; i<=n; i++) {
cin >> a[i];
a[i] -= i*m;
}
vector<int> poss_unchanged;
for (int i=0; i<=n; i++) {
if (a[i] <= 0) { poss_unchanged.push_back(-a[i]); }
}
cout << (n+1) - max_non_dec_subseq(poss_unchanged) << '\n';
}
