#include<stdio.h>
#include<math.h>
double f(double n,double x)
{
if(n==1)
return sqrt(n+x);
else
return sqrt (n+f(n-1,x));
}
int main()
{
double x,n;
scanf("%lf %lf",&x,&n);
printf("%.2lf",f(n,x));
return 0;
}
#include<stdio.h>
#include<math.h>
double f(double n,double x)
{
if(n==1)
return sqrt(n+x);
else
return sqrt (n+f(n-1,x));
}
int main()
{
double x,n;
scanf("%lf %lf",&x,&n);
printf("%.2lf",f(n,x));
return 0;
}