def euler(n):
    s = 0
    for i in range(1,n+1):
        term = 1/i**2
        s = s + term
    x = (6*s)**0.5
    return(x)

def leibniz(n):
    s = 0
    for i in range(n):
        term = (-1)**i/(2*i+1)
        s = s + term
    x = 4*s
    return(x)

def wallis(n):
    p = 1
    for i in range(1,n+1):
        num = (2*i)**2
        den = (2*i-1)*(2*i+1)
        term = num/den
        p = p*term
    x = 2*p
    return(x)

def vieta(n):
    p = 1
    num = 0
    for i in range(1,n+1):
        num = (2 + num)**0.5
        den = 2
        term = num/den
        p = p*term
    x = 2/p
    return(x)

#------------------
n = 100
print(euler(n))
print(leibniz(n))
print(wallis(n))
print(vieta(n))

#------------------

##print("euler")
##print(1000,euler(1000))
##print(10000,euler(10000))
##print(1000000,euler(1000000))
##
##print("leibniz")
##print(1000,leibniz(1000))
##print(10000,leibniz(10000))
##print(1000000,leibniz(1000000))
##
##print("wallis")
##print(1000,wallis(1000))
##print(10000,wallis(10000))
##print(1000000,wallis(1000000))