//naive solution
#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
//alg written with help from chatGPT
int longestNonIncreasingSubseqFromZero(const std::vector<int>& v) {
int n = v.size();
// tails[L] = max possible last element of a nonincreasing subseq
// of length L starting at v[0].
// We'll use 1-based indexing on tails.
std::vector<int> tails(n+1);
int len = 1;
tails[1] = v[0]; // subsequence of length 1 is just {v[0]}
for (int i = 1; i < n; ++i) {
int x = v[i];
// find the largest L in [1..len] with tails[L] >= x
int lo = 1, hi = len, pos = 0;
while (lo <= hi) {
int mid = (lo + hi) / 2;
if (tails[mid] >= x) {
pos = mid; // candidate
lo = mid + 1; // try to go further right
} else {
hi = mid - 1;
}
}
// if pos==0, x > tails[1]=v[0], so it can't follow the 0
if (pos == 0) continue;
if (pos == len) {
// we can extend the longest one
tails[++len] = x;
} else {
// update the best tail for subseqs of length pos+1
tails[pos + 1] = std::max(tails[pos + 1], x);
}
}
return len;
}
int main() {
ios::sync_with_stdio(false);
cin.tie(NULL);
int n, m;
cin >> n >> m;
vector<int> a (n+1, 0);
for(int i = 1; i <= n; ++i) {
cin >> a[i];
a[i] -= m*i;
}
//find the longest nonincreasing subsequence starting with 0
cout << n+1-(longestNonIncreasingSubseqFromZero(a));
//cout << endl << ans;
}
