text: 
  /*
  
   	 Problem Statement : Cops and the Thief Devu
   	 Link : https://www.codechef.com/problems/COPS
   	 Score : accepted
  
   */
  #include <iostream>
  #include<bits/stdc++.h>
  #include<string.h>
  #include<vector>
  using namespace std;
  
  int main()
  {
  	int t;
  	cin>>t;
  	while(t--)
    {
  	    int M,Y,X;
        cin>>M>>X>>Y;
        int houses[100];
        for(int i=0;i<100;i++)
          houses[i] = 1;
  
        int cop_range = X*Y;
        int cop_house[M];
        for(int i=0;i<M;i++)
        {
          cin>>cop_house[i];
        }
        for(int i=0;i<M;i++)
        {
          int start=0,end=100;
          if((cop_house[i] - cop_range) > 0)
            start = (cop_house[i] - cop_range)-1;
          if((cop_house[i] + cop_range) < 100)
            end = (cop_house[i] + cop_range)-1;
  
          for(int j=start;j<=end;j++)
            houses[j] = 0;
  
        }
        int remaining_houses = 0;
        for(int i=0;i<100;i++)
        {
          if(houses[i]==1)
            remaining_houses++;
        }
        cout<<remaining_houses<<'\n';
    }
    return 0;
  }
  