#include<bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int a[N];
int main(){
    int t;
    cin>>t;
    while(t--){
        int n,k;
        cin>>n>>k;
        for(int i=1;i<=n;i++){
            cin>>a[i];
        }
        
        sort(a+1,a+1+n);
        a[n+1]=-1;
        int ans=0,temp=0,num=1,flag=0;
        for(int i=1;i<=n;i++){
            if(a[i]==a[i+1]){
                num++;
                continue;
            }
            if(flag==0){
                flag=1;
                if(num<=k*2+1){
                    ans+=num;
                    temp=a[i]-k+num-1;
                    //cout<<temp<<endl;
                }
                else {
                    temp=a[i]+k;
                    ans+=k*2+1;
                }
            }
            else{
                if(temp<a[i]-k){
                    if(num<=k*2+1){
                        ans+=num;
                        temp=a[i]-k+num-1;
                    }
                    else {
                        temp=a[i]+k;
                        ans+=k*2+1;
                    }
                }
                else{
                    if(num<=a[i]+k-temp){
                        temp+=num;
                        ans+=num;
                    }
                    else {ans+=(a[i]+k-temp);
                        temp=a[i]+k;
                        
                    }
                }
            }
            //cout<<temp<<"   "<<num<<" "<<ans<<endl;
            num=1;
        }
        cout<<ans<<endl;
    }
}