#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<cmath>
#include<cstdlib>
#define ll long long
#define N 100005
using namespace std;

int n; ll a[N],tl,tr;
struct node{ ll x,y;}b[N];
ll read(){
    ll x=0; char ch=getchar(); bool flag=0;
    while (ch<'0' || ch>'9'){ if (ch=='-') flag=1; ch=getchar(); } 
    while (ch>='0' && ch<='9'){ x=x*10+ch-'0'; ch=getchar(); }
    return (flag)?-x:x;
}
bool cmp(const node &u,const node &v){ return u.x<v.x; }
ll calc(ll x,ll y){
    x=max(x,tl);y=min(y,tr);
    if (x<=y) return y-x+1; else return 0;
}
int main(){
    int cas;scanf("%d",&cas);
    while (cas--){
        scanf("%d",&n); tl=read(); tr=read();
        int i;
        for (i=1; i<=n; i++) a[i]=read(); sort(a+1,a+n+1);
        for (i=1; i<n; i++) b[i]=(node){a[i+1]-a[i]+1,a[i]+a[i+1]-1};
        sort(b+1,b+n,cmp);n--;
        ll head=b[1].x,tail=b[1].y,ans=0;
        for (i=2; i<=n; i++)
            if (b[i].x>tail+1){
                ans+=calc(head,tail); head=b[i].x;tail=b[i].y;
            } else tail=max(tail,b[i].y);
        ans+=calc(head,tail); printf("%I64d\n",tr-tl+1-ans);
    }
    return 0;
}