n=int(eval(input()))

a=[[int(i)for i in input().split()]for i in range(n)]

import itertools as it

li=list(it.permutations(list(range(n))))

total=0

for i in li:

    tmp=0

    for j in range(n-1):

        x1,x2=a[i[j]][0],a[i[j+1]][0]

        y1,y2=a[i[j]][1],a[i[j+1]][1]

        tmp=(x1-x2)**2+(y1-y2)**2

        total+=tmp**0.5

print((total/len(li)))
n=int(eval(input()))

a=[[int(i) for i in input().split()] for i in range(n)]



import itertools

import math

pe=itertools.permutations(list(range(n)))

pe=list(pe)

ans=0



for i in pe:

    tmp=0

    for j in range(n-1):

        tmp+=((a[i[j]][0]-a[i[j+1]][0])**2+(a[i[j]][1]-a[i[j+1]][1])**2)**0.5

    ans+=tmp

print((ans/math.factorial(n)))
n = int(eval(input()))
a = [[int(i) for i in input().split()] for i in range(n)]
import itertools as it

li = list(it.permutations(list(range(n))))
total = 0
for i in li:
    tmp = 0
    for j in range(n - 1):
        x1, x2 = a[i[j]][0], a[i[j + 1]][0]
        y1, y2 = a[i[j]][1], a[i[j + 1]][1]
        tmp = (x1 - x2) ** 2 + (y1 - y2) ** 2
        total += tmp**0.5
print((total / len(li)))

n = int(eval(input()))
a = [[int(i) for i in input().split()] for i in range(n)]
import itertools
import math

pe = itertools.permutations(list(range(n)))
pe = list(pe)
ans = 0
for i in pe:
    tmp = 0
    for j in range(n - 1):
        tmp += (
            (a[i[j]][0] - a[i[j + 1]][0]) ** 2 + (a[i[j]][1] - a[i[j + 1]][1]) ** 2
        ) ** 0.5
    ans += tmp
print((ans / math.factorial(n)))

-import itertools as it +import itertools +import math -li = list(it.permutations(list(range(n)))) -total = 0 -for i in li: +pe = itertools.permutations(list(range(n))) +pe = list(pe) +ans = 0 +for i in pe: -        x1, x2 = a[i[j]][0], a[i[j + 1]][0] -        y1, y2 = a[i[j]][1], a[i[j + 1]][1] -        tmp = (x1 - x2) ** 2 + (y1 - y2) ** 2 -        total += tmp**0.5 -print((total / len(li))) +        tmp += ( +            (a[i[j]][0] - a[i[j + 1]][0]) ** 2 + (a[i[j]][1] - a[i[j + 1]][1]) ** 2 +        ) ** 0.5 +    ans += tmp +print((ans / math.factorial(n)))