#include<bits/stdc++.h>
using namespace std;
#define ff first
#define ss second
#define pb push_back
#define int long long
const int N=5005;
vector<int>ans;
int a[N];
int dp[N];
signed main(){
int n,x;
cin>>n>>x;
for(int i=0;i<N;i++){
dp[i]=1e9;
}
for(int i=1;i<=n;i++){
cin>>a[i];
}
dp[0]=0;
for(int i=1;i<=n;i++){
vector<int>tmp(N+1);
tmp[N]=1e9;
for(int j=N-1;j>=0;j--){
tmp[j]=min(tmp[j+1],dp[j]);
}
for(int j=0;j<N;j++){
int l= max(0ll,j-x);
dp[j]= tmp[l]+(a[i]!=j);
}
}
int ans=1e9;
for(int i=0;i<N;i++){
ans=min(ans,dp[i]);
}
cout<<ans;
}
