#include <bits/stdc++.h>
using namespace std;
const int MaxN = 200005;
int n, m, a[MaxN], cnt;
long long b[MaxN], aib[MaxN], ans = 1, dp[MaxN];
pair <int, int> c[MaxN];
void Update(int poz, long long val){
for(int i = poz; i <= cnt; i += (i & -i))
aib[i] = max(aib[i], val);
}
long long Query(int poz){
long long s = 0;
for(int i = poz; i > 0; i -= (i & -i))
s = max(s, aib[i]);
return s;
}
int main()
{
cin >> n >> m;
for(int i = 1; i <= n; i++){
cin >> a[i];
if(1LL * m * i - a[i] >= 0){
b[++cnt] = 1LL * m * i - a[i];
c[cnt] = {b[cnt], cnt};
}
}
sort(c + 1, c + cnt + 1);
int val = 1;
b[c[1].second] = 1;
for(int i = 2; i <= cnt; i++){
if(c[i].first != c[i - 1].first)
val++;
b[c[i].second] = val;
}
for(int i = 1; i <= cnt; i++){
dp[i] = max(dp[i], 1 + Query(b[i]));
Update(b[i], dp[i]);
ans = max(ans, dp[i]);
}
cout << cnt - ans << "\n";
return 0;
}
