import math

def basel(n):
    sumterm = 0
    for i in range(1,n+1):
        term = 1/(i**2)
        sumterm = sumterm + term
##        print(i)
    pi = math.sqrt(6*sumterm)
    return(pi)

def leibniz(n):
    sumterm = 0
    sign = 1
    for i in range(1,2*n,2):
        term = sign/i
        sumterm = sumterm + term
        sign = -sign
##        print(i)
    return(4*sumterm)