#include<bits/stdc++.h>

using namespace std;

double f(double x,double n){

if(n==1) return x/(1+x); 

else return x/(n+f(x,n-1));

}

int main(){ 

double n,x; 

cin>>x>>n;

cout<<fixed<<setprecision(2)<<f(x,n);

}

题目：f(x,n)=x/(n+x/((n-1)+x/(……+x/(1+x)))