View Code of Problem 48

#include<stdio.h>
#include<string.h>
#include<math.h>

int main(){

	double a,sum=0,b,n;
	scanf("%lf",&n);
	a=2,b=1;
	while(n--){
	
		sum+=a/b;
		int t=a;
		a=a+b;
		b=t;
	
	}
	printf("%.6lf",sum);
}