#include <bits/stdc++.h>
using namespace std;
int n,price[51],isavilable[51],dp[1001][51];
int func(int i, int value)
{
    if(i>=n)
    {
        if(value == 0) return 1;
        else return 0;
    }

    if(value == 0) return 1;


    if(dp[value][i] != -1)
        return dp[value][i];

    int result = 0;

    for(int j = 0; j <= isavilable[i]; j++)
    {
        if(value-price[i]*j >= 0)
            result = (result%100000007 + func(i+1,value-(price[i]*j)))%100000007;
    }

    return dp[value][i]=result;
}
int main()
{
    int T,value,cases=0;
    scanf("%d",&T);
    while(T--)
    {
        scanf("%d %d", &n, &value);
        for(int i = 0; i <= value+1; i++)
        {
            for(int j = 0; j <= n; j++)
            {
                dp[i][j]= -1;
            }
        }
        for(int i = 0; i < n; i++)  scanf("%d",&price[i]);
        for(int i = 0; i < n; i++)  scanf("%d",&isavilable[i]);
        printf("Case %d: %d\n",++cases,func(0,value));
    }
    return 0;
}