View Code of Problem 48

#include<iostream>
#include<iomanip>
#include<string>
using namespace std;
int main()
{
	int n;
	double a=1,b=2,c,sum;
	while(cin>>n)
	{
		sum=0;
		for(int i=0;i<n;i++)
		{
			c=b/a;
			b=a+b;
			a=b-a;
			sum+=c;
		}
		cout<<fixed<<setprecision(6)<<sum<<endl;
	
	}
	
	return 0;
}