#include<bits/stdc++.h>

 #define LL long long

 #define LD long double

 #define  N 100005

 using namespace std;

 inline int ra()

 {

     int x=,f=; char ch=getchar();

     while (ch<'' || ch>'') {if (ch=='-') f=-; ch=getchar();}

     while (ch>='' && ch<='') {x=x*+ch-''; ch=getchar();}

     return x*f;

 }

 double f[],p[];

 double ksm(double a, int p)

 {

     double ans=;

     for (;p;p>>=,a*=a)

         if (p&)

             ans*=a;

     return ans;

 }

 int main()

 {

     freopen("tribbles.in","r",stdin);

     freopen("tribbles.out","w",stdout);

     int T=ra();

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

     {

         int n=ra(),k=ra(),m=ra();

         for (int i=; i<n; i++) scanf("%lf",&p[i]);

         memset(f,,sizeof(f));

         f[]=; f[]=p[];

         for (int i=; i<=m; i++)

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

                 f[i]+=p[j]*ksm(f[i-],j);

         printf("Case #%d: %.7lf\n",t,ksm(f[m],k));

     }

     return ;

 }