#include<iostream>
#include<stdio.h>
#include<string.h>
#include<math.h>
#define mod 100000007

//5 /5 8 11 15 18 /18 using one coin several time
//how many ways it can be created



using namespace std;
int n,cap;
int val[102];
int num[102];
bool flag;
int dp[102][1002][25];

int coin(int i,int w,int c)
{
    if(w==0)
    {
        return 1;
    }
    if(i>=n)
    {
        if(w==0)
        {

            return 1;
        }
        else if(w!=0)
        {
            return 0;
        }

    }

    if(dp[i][w][c]!=-1)
    {
        return dp[i][w][c];
    }

    int ret1,ret2;
    ret1=ret2=0;


    if(w-val[i]>=0)
    {
        if(c<num[i])
        {
            ret1=coin(i,w-val[i],c+1)%mod;
        }
    }

        ret2=coin(i+1,w,0)%mod;

    dp[i][w][c]=(ret1+ret2)%mod;

    return dp[i][w][c];

}

int main()
{
    int i,j,k,t;
//    5 types of coins: 50-cent, 25-cent, 10-cent, 5-cent, and 1-cent
    scanf("%d",&t);
    for(int kk1=1;kk1<=t;kk1++)
    {
        scanf("%d %d",&n,&cap);
        for(i=0;i<n;i++)
        {
            scanf("%d",&val[i]);
        }
        for(i=0;i<n;i++)
        {
            scanf("%d",&num[i]);
        }

        memset(dp,-1,sizeof(dp));
        printf("Case %d: ",kk1);
        printf("%d\n",(coin(0,cap,0)));


    }



}