View Code of Problem 48

import java.util.Scanner;
 
public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		int n = scanner.nextInt();
          	double a=1;
          	double b=2;
          	double sum=0;
          for(int i=0;i<n;i++){
            	double c=b/a;
            	double temp=b;
            	sum=c+sum;
            	b=b+a;
            	a=temp;
            	
            	
            	
            	
          }
		System.out.println(String.format("%.6f",sum));
	}
}