1166：求f(x,n)

#include <iostream>
#include <cmath>
#include <iomanip>
using namespace std;
double f (double x,double n)
{
    if(n == 1)
    {
        return sqrt(1+x);
    }
    return sqrt(n+f(x,n-1));
}
int main()
{
    double x,n;
    cin>>x>>n;
    cout<<fixed<<setprecision(2)<<f(x,n)<<endl;
    return 0;
}