View Code of Problem 71

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