#include<cstdio>

 #include<cstring>

 #define FOR(a,b,c) for(int a=(b);a<=(c);a++)

 using namespace std;

 const int N = +;

 double p[N] , f[N];

 int n,m,k;

 double pow(double x,int p) {

     double ans=,tmp=x;

     while(p) {

         if(p&) ans*=tmp;

         tmp*=tmp; p>>=;

     }

     return ans;

 }

 int main() {

     int T,kase=;

     scanf("%d",&T);

     while(T--) {

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

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

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

         FOR(i,,m) {

             f[i]=;

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

         }

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

     }

     return ;

 }