View Code of Problem 71

#include<stdio.h>
int main()
{
	int n;
	double a=1,b=2,sum,c;
	scanf("%d",&n);
	for(int i=0;i<n;i++)
	{
		sum+=(b/a);
		c=b;
		b=a+b;
		a=c;
	}
	printf("%.2lf",sum);
	return 0;
}