View Code of Problem 48

#include<bits/stdc++.h>
using namespace std;
int main()
{
	  double n,c,a=2,b=1,s=0; 
	  cin>>n;
	  for(int i=1;i<=n;i++)
	  {
	  	s+=a/b;
		c=a+b;
	  	b=a;
	  	a=c;
	   } 
	   printf("%.6lf\n",s);
	   return 0;
}