n = int(eval(input()))

L = []

for i in range(n):

    x, y = list(map(int, input().split()))

    L.append([x, y])



import itertools

import math



ans = 0

for i in itertools.permutations(list(range(n))):

    for j in range(n-1):

        ans += math.sqrt((L[i[j+1]][0]-L[i[j]][0])**2+(L[i[j+1]][1]-L[i[j]][1])**2)

for i in range(1,n+1):

    ans /= i

print(ans)

n = int(eval(input()))

X = []

Y = []



for i in range(n):

    x, y = list(map(int, input().split()))

    X.append(x)

    Y.append(y)



import math

import itertools

ans = 0

for p in list(itertools.permutations(list(range(n)))):

    for i in range(len(p)):

        if i == len(p)-1:

            continue

        ans += math.sqrt((X[p[i]]-X[p[i+1]])**2+(Y[p[i]]-Y[p[i+1]])**2)

ans /= math.factorial(n)

print(ans)
n = int(eval(input()))
L = []
for i in range(n):
    x, y = list(map(int, input().split()))
    L.append([x, y])
import itertools
import math

ans = 0
for i in itertools.permutations(list(range(n))):
    for j in range(n - 1):
        ans += math.sqrt(
            (L[i[j + 1]][0] - L[i[j]][0]) ** 2 + (L[i[j + 1]][1] - L[i[j]][1]) ** 2
        )
for i in range(1, n + 1):
    ans /= i
print(ans)

n = int(eval(input()))
X = []
Y = []
for i in range(n):
    x, y = list(map(int, input().split()))
    X.append(x)
    Y.append(y)
import math
import itertools

ans = 0
for p in list(itertools.permutations(list(range(n)))):
    for i in range(len(p)):
        if i == len(p) - 1:
            continue
        ans += math.sqrt((X[p[i]] - X[p[i + 1]]) ** 2 + (Y[p[i]] - Y[p[i + 1]]) ** 2)
ans /= math.factorial(n)
print(ans)

-L = [] +X = [] +Y = [] -    L.append([x, y]) +    X.append(x) +    Y.append(y) +import math -import math -for i in itertools.permutations(list(range(n))): -    for j in range(n - 1): -        ans += math.sqrt( -            (L[i[j + 1]][0] - L[i[j]][0]) ** 2 + (L[i[j + 1]][1] - L[i[j]][1]) ** 2 -        ) -for i in range(1, n + 1): -    ans /= i +for p in list(itertools.permutations(list(range(n)))): +    for i in range(len(p)): +        if i == len(p) - 1: +            continue +        ans += math.sqrt((X[p[i]] - X[p[i + 1]]) ** 2 + (Y[p[i]] - Y[p[i + 1]]) ** 2) +ans /= math.factorial(n)