from pylab import *

vnutri=0;
xx=empty(100)
yy=empty(100)
for i in range(100):   
	x = np.random.random()  
	y = np.random.random()
	if (x*x+y*y)<1:
		vnutri=vnutri+1
	xx[i]=x
	yy[i]=y
print 4.*vnutri/100.
plot(xx,yy,"o")
xxx=empty(1000)
yyy=empty(1000)
for  i in range(1000):
	xxx[i]=i/1000.
	yyy[i]=sqrt(1.-xxx[i]*xxx[i])
plot(xxx,yyy)	
show()