# include <stdio.h>
# include <math.h>
void main ()
{ double n,sum,x;
  int m,i;
           
       while(scanf("%lf%d",&n,&m)!=EOF)
       {    x=n;sum=0.0;
           for(i=1;i<m;i++)
           { n=sqrt(n);
             sum+=n;
           }
           sum=sum+x;
         
       }
          printf("%.2lf\n",sum);
}