#include<bits/stdc++.h>
using namespace std;
#define ll long long  
const double PI = acos(-1);
const double epx = 1e-12;
bool cmp(array<double,3> a,array<double,3> b)
{
	return a[2] < b[2];
}

void solve()
{
	int n,k;
	cin>>n>>k;
	vector<array<double,3>  > cood;
	cout<<setprecision(8);
	
	//double add = 0;
	for(int i=0;i<n;i++)
	{	int x,y;
	
		cin>>x>>y ;
		double ang = 0;
		if(x == 0)
		{
			if(y  == 0)
			{	k -- ;
				n -- ;
				continue ;
			}	
			else if( y > 0)
				ang = PI/2;
			else 
				ang = PI/2 + PI;
		}
		else if(y == 0)
		{
			if(x > 0)
				ang = 0;	
			else 
				ang = PI; 
		}
		else 
		{	
			ang = atan(1.0*y/x);
			//cout<<ang<<endl;
			
		//cout<<cood[i][2]<<endl;
			if(x <-epx && y> epx)
			{	//cout<<i<<' '<<1<<endl;
			
				ang += PI;
			}
			else if(x <-epx &&y <-epx )
			{	//cout<<i<<' '<<2<<endl;
				ang += PI;
			}
			else if(x  > epx && y <-epx)
			{	//cout<<i<<' '<<3<<endl;
				ang += 2*PI;
			}
		}	
		cood.push_back({x,y,ang});
		
	}
	
	
	for(int i=0;i<n;i++)
	{
		cood.push_back(cood[i]);
		cood[i+n][2] += 2*PI;
		
	}
	sort(cood.begin(),cood.end(),cmp);
	double mi = 0 ;
	for(int i=k;i<2*n;i++)
	{	//cout<<cood[i][2]<<" "<<cood[i-k][2]<<endl;
	
		mi = max(mi,cood[i][2] - cood[i-k][2]);
	}
	cout<<mi<<endl;
	
	
	
	
}
signed main (){
	std::ios::sync_with_stdio(false);  
	cin.tie(NULL); 
	cout.tie(NULL);
	
	
	int t;
	cin>>t;
	while(t--)
		solve();
}