View Code of Problem 71

#include <stdio.h>
int main()
{
	float t,a=2.0,b=1.0,sum;
  	int n;
  	scanf("%d",&n);
  	while(n--)
        {
        	sum+=a/b;
          	t=a;
          	a=a+b;
          	b=t;   
        }
  	
	printf("%.2f",sum);



}