import io,os
import math

input = io.BytesIO(os.read(0, os.fstat(0).st_size)).readline



def getangle(x,y):

    if x == 0:  
        if y > 0:  return math.pi / 2
        if y < 0:  return 3 * math.pi / 2 
    if y == 0:
        if x < 0:  return math.pi
        if x > 0:  return 0

    if x > 0 and y > 0:
        return math.atan(y/x)

    if x < 0 and y > 0:
        return math.pi - math.atan(-y/x)

    if x < 0 and y < 0:
        return math.pi + math.atan(y/x)
   
    if x > 0 and y < 0:
        return 2 * math.pi - math.atan(-y/x)



def main():

    n,k = map(int,input().split())
    points = []
    for _ in range(n):
        x,y = map(int,input().split())
        angle = getangle(x,y)
        points.append(angle)

    if k == n:
        print(2*math.pi)
        return 


    points.sort()

    points2 = [num+2*math.pi for num in points]

    
    points.extend(points2)

    ans = 0
    
    for i in range(k,2*n):
        ans = max(ans,  points[i] - points[i-k])

    print(ans)
        
        
        
      
    
    






T = int(input())
t = 1
while t <= T:
    main()
    t += 1