#include<stdio.h>
int main()
{
int a,G,B;
double m,n;
scanf("%d",&a);
scanf("%lf %lf",&m,&n);
if(a==G)
printf("%.1lf",n+0.5m);
else if(a==B)
printf("%.1lf",1.1m+0.6*n);
else
printf("Wrong input");
return 0;
}