# pi sayisinin hesabi
import math
n=int(raw_input("N sayisini giriniz: "))
sum=0
for i in range(1,n,1): sum = sum+(1.0/(i*i))
p=math.sqrt(6*sum)
print "pi sayisinin yaklasik degeri =",p
import math
n=int(raw_input("N sayisini giriniz: "))
sum=0
for i in range(1,n,1): sum = sum+(1.0/(i*i))
p=math.sqrt(6*sum)
print "pi sayisinin yaklasik degeri =",p
