#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <algorithm>

 #include <queue>

 #include <vector>

 #include <cmath>

 #define min(a, b) ((a) < (b) ? (a) : (b))

 #define max(a, b) ((a) > (b) ? (a) : (b))

 #define abs(a) ((a) < 0 ? (-1 * (a)) : (a))

 inline void swap(int &a, int &b)

 {

     long long tmp = a;a = b;b = tmp;

 }

 inline void read(int &x)

 {

     x = ;char ch = getchar(), c = ch;

     while(ch < '' || ch > '') c = ch, ch = getchar();

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

     if(c == '-') x = -x;

 }

 const int INF = 0x3f3f3f3f;

 const int MAXN =  + ;

 int t,n,k,m;

 double p[MAXN], dp[MAXN];

 /*double pow(double a, int b)

 {

     double r = 1, base = a;

     for(;b;b >>= 1)

     {

         if(b & 1) r *= base;

         base *= base;

     }

     return r;

 }*/

 int main()

 {

     read(t);

     int ca = ;

     for(;t;-- t)

     {

         ++ ca;

         memset(dp, , sizeof(dp));

         read(n), read(k), read(m);

         -- n;

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

         dp[] = p[];

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

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

                 dp[i] += p[j] * pow(dp[i - ], j);

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

     }

     return ;

 }