import numpy as np

from itertools import permutations

import math



n = int(eval(input()))



li = []

for _ in range(n):

    i, j = list(map(int, input().split()))

    li.append(np.array([i, j]))



li2 = permutations(li)



re = []

for a in li2:

    dis = 0 

    for (x1,y1),(x2,y2) in zip(a,a[1:]):

        dis += math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2))

    re.append(dis)



print((np.average(re)))

import numpy as np

from itertools import permutations

import math



n = int(eval(input()))



li = []

for _ in range(n):

    i, j = list(map(int, input().split()))

    li.append(np.array([i, j]))



li2 = permutations(li)



re = []

for a in li2:

    dis = 0 

    for (x1,y1),(x2,y2) in zip(a,a[1:]): 

        x = x1-x2

        y = y1-y2

        dis += math.sqrt(x * x + y * y)

    re.append(dis)



print((np.average(re)))

import numpy as np
from itertools import permutations
import math

n = int(eval(input()))
li = []
for _ in range(n):
    i, j = list(map(int, input().split()))
    li.append(np.array([i, j]))
li2 = permutations(li)
re = []
for a in li2:
    dis = 0
    for (x1, y1), (x2, y2) in zip(a, a[1:]):
        dis += math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2))
    re.append(dis)
print((np.average(re)))

import numpy as np
from itertools import permutations
import math

n = int(eval(input()))
li = []
for _ in range(n):
    i, j = list(map(int, input().split()))
    li.append(np.array([i, j]))
li2 = permutations(li)
re = []
for a in li2:
    dis = 0
    for (x1, y1), (x2, y2) in zip(a, a[1:]):
        x = x1 - x2
        y = y1 - y2
        dis += math.sqrt(x * x + y * y)
    re.append(dis)
print((np.average(re)))

-        dis += math.sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2)) +        x = x1 - x2 +        y = y1 - y2 +        dis += math.sqrt(x * x + y * y)