//UVA 11021

 #include<cmath>

 #include<cstdio>

 #define rep(i,n) for(int i=0;i<n;++i)

 #define F(i,j,n) for(int i=j;i<=n;++i)

 const int N=;

 int n,m,k;

 double p[N],f[N];

 int main(){

     int t;

     scanf("%d",&t);

     F(cs,,t){

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

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

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

         F(i,,m){

             f[i]=;

             rep(j,n) f[i]+=p[j]*pow(f[i-],j);

         }

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

     }

     return ;

 }