#include <bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define ll long long
#define ld double
#define llu long long unsigned

int main()
{
    fast;
    int t;
    cin>>t;
    for( int c = 1 ; c <= t ; c++ )
    {
        cout<<"Case "<<c<<": ";
        int n , k;
        cin>>n>>k;
        if( n < k )
        {
            cout<<0<<endl;
            continue;
        }
        llu ans = 1;
        for( int i = 1 ; i <= k ; i++ )
        {
            ans *= pow( n - i + 1 , 2 );
        }
        for( int i = 1 ; i <= k ; i++ )
            ans /= i;
        cout<<ans<<endl;
    }
    return 0;
}