// BOOMERANG CREWS
// Official Solution by Jacob Plachta

#define DEBUG 0

#include <algorithm>
#include <functional>
#include <numeric>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <complex>
#include <cstdlib>
#include <ctime>
#include <cstring>
#include <cassert>
#include <string>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <sstream>
using namespace std;

#define LL long long
#define LD long double
#define PR pair<int,int>

#define Fox(i,n) for (i=0; i<n; i++)
#define Fox1(i,n) for (i=1; i<=n; i++)
#define FoxI(i,a,b) for (i=a; i<=b; i++)
#define FoxR(i,n) for (i=(n)-1; i>=0; i--)
#define FoxR1(i,n) for (i=n; i>0; i--)
#define FoxRI(i,a,b) for (i=b; i>=a; i--)
#define Foxen(i,s) for (i=s.begin(); i!=s.end(); i++)
#define Min(a,b) a=min(a,b)
#define Max(a,b) a=max(a,b)
#define Sz(s) int((s).size())
#define All(s) (s).begin(),(s).end()
#define Fill(s,v) memset(s,v,sizeof(s))
#define pb push_back
#define mp make_pair
#define x first
#define y second

template<typename T> T Abs(T x) { return(x<0 ? -x : x); }
template<typename T> T Sqr(T x) { return(x*x); }
string plural(string s) { return(Sz(s) && s[Sz(s)-1]=='x' ? s+"en" : s+"s"); }

const int INF = (int)1e9;
const LD EPS = 1e-9;
const LD PI = acos(-1.0);

//#if DEBUG
#define GETCHAR getchar
/*#else
#define GETCHAR getchar_unlocked
#endif*/

bool Read(int &x)
{
	char c,r=0,n=0;
	x=0;
		for(;;)
		{
			c=GETCHAR();
				if ((c<0) && (!r))
					return(0);
				if ((c=='-') && (!r))
					n=1;
				else
				if ((c>='0') && (c<='9'))
					x=x*10+c-'0',r=1;
				else
				if (r)
					break;
		}
		if (n)
			x=-x;
	return(1);
}

int main()
{
		if (DEBUG)
			freopen("in.txt","r",stdin);
	int T,t;
	int N,M,D;
	int i,j,c,free;
	int r1,r2,m;
	static int A[100000],B[100000];
	set<PR> S;
	set<PR>::iterator I;
	Read(T);
		Fox1(t,T)
		{
			Read(N),Read(M),Read(D);
				Fox(i,N)
					Read(A[i]);
				Fox(i,M)
					Read(B[i]);
			sort(A,A+N);
			reverse(A,A+N);
			j=free=0;
				Fox(i,M)
					if (B[i]<=A[0])
						free++;
					else
						B[j++]=B[i];
			M=j;
			sort(B,B+M);
			r1=0,r2=min(N,M);
				while (r2>r1)
				{
					m=(r1+r2+1)>>1;
					S.clear();
						Fox(i,m)
							S.insert(mp(A[i]%D,i));
					c=1;
						Fox(i,m)
						{
							I=S.lower_bound(mp(B[i]%D,-1));
								if (I==S.end())
									I=S.begin();
							j=A[I->y],S.erase(I);
							c+=(B[i]-j+D-1)/D-1;
								if (c>N-m)
									goto Bad;
						}
					r1=m;
					continue;
Bad:;
					r2=m-1;
				}
			printf("Case #%d: %d\n",t,free+r1);
		}
	return(0);
}