View Code of Problem 48

#include <stdio.h>


int main()
{

	double fn1=1,fn2=2,fn;
	double sum=0,temp;
	int n;
	scanf("%d",&n);
	while(n--)
	{
		fn=fn2/fn1;
		temp=fn2;
		fn2=fn1+fn2;
		fn1=temp;
		sum+=fn;
	}
	
	
	
	printf("%.6f",sum);

	
}