#include #include #include #include #include using namespace std; #define MAXROUND 100005 double safemoney[MAXROUND]; double roundmoney[MAXROUND]; double p[MAXROUND]; char str[256]; inline double ln(double inc) { return log(inc); } int main() { int n,W; scanf("%d %d",&n,&W); for(int i=0;i=0;i--) { double tmp=p[i]*roundmoney[i+1]+(1-p[i])*safemoney[i]; roundmoney[i]=max(tmp,roundmoney[i]); } double ans=(exp(roundmoney[0])-1)*W; printf("$%.2f\n",ans); }