#3.17
import random
from matplotlib import pyplot as plt
import math
a=[]
#a[0]=x1
#a[1]=y1
#a[2]=x2
#a[3]=y2
x=[]
y=[]
n,N,M=0,10,0
for _ in range (N):
    for i in range (4):
        a.append(random.uniform(-1, 1))
    if ((a[0])**2 + (a[1])**2)<= 1 and ((a[2])**2 + (a[3])**2) <= 1:
        M+=1
        if ((a[2] - a[0])**2 + (a[3] - a[1])**2)<1:
            n+=1
            #print(math.sqrt((a[2] - a[0])**2 + (a[3] - a[1])**2))
    a=[]

print(n/M)
'''
plt.plot(x,y, linestyle="",marker="o")
plt.title('PLOT')
plt.show()
'''