1231

/*
 *  Shafaetsplanet.com
 */
#include <algorithm>
#include <bitset>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <deque>
#include <fstream>
#include <iostream>
#include <list>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <utility>
#include <vector>

#define stream istringstream
#define rep(i,n) for(int i=0; i<(int)n; i++)
#define repv(i,n) for(int i=n-1; i>=0; i--)
#define repl(i,n) for(int i=1; i<=(int)n; i++)
#define replv(i,n) for(int i=n; i>=1; i--)


#define INF (1<<28)
#define PI 3.14159265358979323846264338327950
#define pb(x) push_back(x)
#define ppb pop_back
#define all(x) x.begin(),x.end()
#define mem(x,y) memset(x,y,sizeof(x));
#define eps 1e-9
#define pii pair<int,int>
#define pmp make_pair


#define sdi(x) scanf("%d",&x)
#define sdii(x,y) scanf("%d%d",&x,&y)
#define SDs(x) scanf("%s",x)
#define uu first
#define vv second

using namespace std;

template<class T> inline T gcd(T a,T b) {if(a<0)return
gcd(-a,b);if(b<0)return gcd(a,-b);return (b==0)?a:gcd(b,a%b);}
template<class T> inline T lcm(T a,T b) {if(a<0)return
lcm(-a,b);if(b<0)return lcm(a,-b);return a*(b/gcd(a,b));}
template<class T> inline T sqr(T x){return x*x;}
template<class T> T power(T N,T P){ return (P==0)?  1: N*power(N,P-1); }

typedef long long i64;
typedef unsigned long long ui64;

#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)

//bool operator < ( const node& p ) const {      return dist > p.dist;   }

int fx[]={0,0,-1,+1,-1,-1,+1,+1};
int fy[]={-1,+1,0,0,-1,+1,-1,+1};

int Set(int N,int pos){return N=N | (1<<pos);}
int Reset(int N,int pos){return N= N & ~(1<<pos);}
int check(int N,int pos){return (N & (1<<pos));}
int toggle(int N,int pos){if(check(N,pos))return N=Reset(N,pos);return N=Set(N,pos);}
void PBIT(int N){   printf("("); for(int i=10;i>=0;i--) {bool x=check(N,i);cout<<x;}    puts(")");}




int c[200],a[200];
int n,k;
int dp[1003][51];
int MOD=100000007;
int call(int amount,int idx)
{
    if(idx>n)
    {
        if(amount==k) return 1;
        return 0;
    }

    if(amount>k) return 0;
    if(amount==k) return 1;
    if(dp[amount][idx]!=-1) return dp[amount][idx];
    int ret=0;

    for(int take=1;take<=c[idx];take++)
    {
        if(amount+a[idx]*take<=k)
        ret+=call(amount+a[idx]*take,idx+1)%MOD;
        else break;
    }
    ret+=call(amount,idx+1)%MOD;
    return dp[amount][idx]=ret%MOD;

}
int main()
{
    //READ("in");
    int t,kas=0;
    cin>>t;
    while(t--)
    {
        mem(dp,-1);
        sdii(n,k);
        repl(i,n)sdi(a[i]);
        repl(i,n)sdi(c[i]);
        int ret=call(0,1)%MOD;
        printf("Case %d: %d\n",++kas,ret);
    }
}