#include<cstdio>
#include<iostream>
#include<cmath>
#define M 3.1415926535897932384626
using namespace std;
int main()
{
//	freopen("1.txt","r",stdin);
	int cc,k,n;
	double d;
	scanf("%d",&cc);
	for(k=1;k<=cc;k++)
	{
		scanf("%lf%d",&d,&n);
		printf("Scenario #%d:\n%.3lf\n\n",k,d/(1.0+1.0/sin(M/n)));		
	}
	return 0;
}