#pragma comment(linker, "/STACK:102400000,102400000")
#include <iostream>
#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#include <string>

using namespace std;

long long a[100005],T,L,R,n;

struct Tnode 
{
    long long x,y;
} b[100005];

bool cmp(Tnode a,Tnode b)
{
    return a.x<b.x;
}
int main()
{
    
    cin >> T;
    for (;T>0;T--)
    {
        cin >> n>> L >> R;
        for (int i=1;i<=n;i++)
        {
            cin >> a[i];
        }
        sort(a+1,a+n+1);
        long long ans=0;
       
        for (int i=2;i<=n;i++)
           {
             b[i].x=a[i]-a[i-1]+1LL;
             b[i].y=a[i]+a[i-1]-1LL;
           }
         
           b[1].x=0;b[1].y=L-1LL;
           n++;
           b[n].x=R+1LL;b[n].y=1000000000000000005LL;
           sort(b+1,b+n+1,cmp);
           ans=0;
           long long Max=b[1].y;
           for (int i=1;i<=n;i++)
           {
                 if (b[i].x>Max) ans+=b[i].x-Max-1LL;
                 Max=max(Max,b[i].y);
           }
        cout << ans << endl;
    }
    return 0;
}