#include<bits/stdc++.h>
using namespace std;
double f(double x,double n){
    if(n==1) return 1/(x+1);
    return 1/(n+f(x,n-1));
}
int main(){
    double a,b;
    cin>>a>>b;
    printf("%.2f",f(a,b));
    return 0;
}