import math
from cmath import phase

stevilo = int(input())
class strelci():
    def __init__(self, x, y, r):
        self.x = x
        self.y = y
        self.radius = r
        self.kot = []
    def simplify_angle(self):
        i = 0
        j = 0
        dolzina = len(self.kot)
        #print(self.kot, dolzina)
        while i < dolzina:
            while j < dolzina and i < dolzina:
                if  i != j and self.kot[j][0] >= self.kot[i][0]:
                    if self.kot[j][0] > self.kot[i][1]:
                        #they are not touching
                        j += 1
                        continue
                    if self.kot[j][1] <= self.kot[i][1]:
                        #this means the angle is contained, delete it
                        dolzina -= 1
                        del self.kot[j]
                        i,j = 0,0
                        continue
                    #print(self.kot[i], self.kot[j])
                    self.kot[i][1] = self.kot[j][1]
                    #we extend the first arc, so it's 1st + 2nd
                    dolzina -= 1
                    del self.kot[j]
                    i,j = 0,0
                    #print(self.kot, i, j)
                    continue
                j += 1
            j = 0
            i += 1
        #print (self.kot)
    def addup(self):
        #print (self.kot)
        probability = 0
        for i in self.kot:
            probability+=i[1]-i[0]
        return 1-probability/(2*math.pi)


vsi = []
for _ in range(stevilo):
    x,y,r = map(int, input().split())
    vsi.append(strelci(x, y, r))

probability = []

for i in range(len(vsi)):
    for j in range(len(vsi)):
        if i != j:
            razdalja = math.hypot(vsi[i].x-vsi[j].x, vsi[i].y-vsi[j].y)
            angle = math.asin(vsi[j].radius/razdalja)
            #center_angle = math.asin((vsi[j].y-vsi[i].y)/razdalja)
            center_angle = phase(complex(vsi[j].x-vsi[i].x, vsi[j].y-vsi[i].y))
            if center_angle < 0:
                center_angle = math.pi-center_angle
            #print (center_angle-angle, center_angle+angle)
            if center_angle-angle > 0:
                vsi[i].kot.append([center_angle-angle, center_angle+angle])
            else:
                vsi[i].kot.append([center_angle-angle+2*math.pi, 2*math.pi])
                vsi[i].kot.append([0, center_angle+angle])
    vsi[i].simplify_angle()
    probability.append(vsi[i].addup())

i = 1
for x in probability:
    i*=x
print("%.6f"%round(i,6))