#include <cstdio>

 #include <cmath>

 const int maxn =  + ;

 long double logF[maxn *  + ];

 long double logC(int n, int m)

 {

     return logF[n] - logF[m] - logF[n-m];

 }

 int main()

 {

     //freopen("in.txt", "r", stdin);

     for(int i = ; i <= maxn*; ++i)

         logF[i] = logF[i-] + log(i);

     int n, kase = ;

     double p;

     while(scanf("%d%lf", &n, &p) == )

     {

         double ans = 0.0;

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

         {

             long double c = logC(*n-i, n);

             long double v1 = c + (n+)*log(p) + (n-i)*log(-p);

             long double v2 = c + (n+)*log(-p) + (n-i)*log(p);

             ans += i * (exp(v1) + exp(v2));

         }

         printf("Case %d: %.6f\n", ++kase, ans);

     }

     return ;

 }