View Code of Problem 48

#include<stdio.h>
#include<string.h>
int main()
{
	int i,n;
	double sum,x1,x2,x;
	scanf("%d",&n);
	x1 = 2;
	x2 = 1;
	for (i = 1;i <= n;i++)
	{
		x = x1;
		sum+=(x1/x2);
		x1+=x2;
		x2 = x;
	}
	printf("%.6lf",sum);
	return 0;
}