#include <iostream>

 #include<cstdio>

 #include<cstring>

 #include<algorithm>

 using namespace std;

 double p[];

 double dp[];

 int flag[],n;

 double po(double a,int k)

 {

     double b = 1.0;

     while(k)

     {

         if(k&)

         b = a*b;

         a = a*a;

         k = k/;

     }

     return b;

 }

 double dfs(int step)

 {

     int i;

     if(flag[step])

     return dp[step];

     if(step == )

     return p[];

     double ans = p[],temp;

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

     {

         temp = p[i];

         temp *= po(dfs(step-),i);

         ans += temp;

     }

     flag[step] = ;

     return dp[step] = ans;

 }

 int main()

 {

     int t,cas = ,i,m,k;

     double ans,temp;

     scanf("%d",&t);

     while(t--)

     {

         scanf("%d%d%d",&n,&k,&m);

         memset(flag,,sizeof(flag));

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

         scanf("%lf",&p[i]);

         if(m == )

         {

             printf("Case #%d: %.7lf\n",cas++,0.0);

             continue;

         }

         ans = ;

         temp = dfs(m);

         for(i = ;i < k;i ++)

         ans *= temp;

         printf("Case #%d: %.7lf\n",cas++,ans);

     }

     return ;

 }