#include <cstdio>

#include <cstring>

#include <iostream>

#include <cmath>

#include <algorithm>

#include <queue>

#include <vector>

using namespace std;

const int maxe = ;

const int maxn = ;

const int INF  = 0x3f3f3f;

float dp[maxn];

long long C[maxn][maxn];

long long A[maxn][maxn];

int main()

{

    //freopen("E:\\acm\\input.txt","r",stdin);

    int T;

    cin>>T;

    for(int i=;i<=;i++)  C[i][] = ;

    A[][] = ;

    for(int i=;i<=;i++)  A[i][i] = A[i-][i-]*i;

    for(int n=;n<=;n++)

        for(int k=;k<=n;k++){

            C[n][k] = C[n][k-] * (n-k+)/k;

            A[n][k] = C[n][k]*A[k][k];

        }

    for(int t=;t<=T;t++){

        int n,k;

        cin>>n>>k;

        printf("Case %d: ",t);

        dp[] = ;

        if(k > n )     printf("0\n");

        else if(k ==  ) printf("1\n");

        else{

            cout<<A[n][k]*C[n][k]<<endl;

        }

    }

}