#include<bits/stdc++.h>
using namespace std;




int main()
{
    int n,banaitehbe,i,j,k,l,t,cas;
    cin>>t;
    for(cas=1;cas<=t;cas++)
    {
        cin>>n>>banaitehbe;
        int value[n+5],koyta[n+5],dp[banaitehbe+5];
        for(i=0;i<n;i++)
            cin>>value[i];
        for(i=0;i<n;i++)
            cin>>koyta[i];
        memset(dp,0,sizeof(dp));
        dp[0]=1;

        for(i=0;i<n;i++)
        {
            for(j=banaitehbe;j>=1;j--)
            {
                for(k=1;k<=koyta[i];k++)
                {
                    if(j>=(value[i]*k))
                        dp[j]=(dp[j]+dp[j-(value[i]*k)])%100000007;
                }
              //  cout<<"dp[j] "<<dp[j]<<endl;
            }
           /* for(l=1;l<=banaitehbe;l++)
                cout<<dp[l]<<" ";
                */
              //  cout<<endl;
        }
        cout<<"Case "<<cas<<": "<<dp[banaitehbe]<<endl;
    }
    return 0;
}