from itertools import permutations

N = int(eval(input()))

xy = [list(map(int, input().split())) for _ in range(N)]



ans = 0

l = list(permutations(xy,N))

for i in l:

  for j in range(N-1):

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

print((ans/len(l)))
from itertools import permutations

n = int(eval(input()))

xy = [list(map(int, input().split())) for _ in range(n)]



ans = 0

count = 0

for i in permutations(list(range(n)), n):

  for j in range(n-1):

    ans += ((xy[i[j]][0] - xy[i[j+1]][0])**2 + (xy[i[j]][1] - xy[i[j+1]][1])**2)**0.5

  count += 1



print((ans/count))
from itertools import permutations

N = int(eval(input()))
xy = [list(map(int, input().split())) for _ in range(N)]
ans = 0
l = list(permutations(xy, N))
for i in l:
    for j in range(N - 1):
        ans += ((i[j][0] - i[j + 1][0]) ** 2 + (i[j][1] - i[j + 1][1]) ** 2) ** 0.5
print((ans / len(l)))

from itertools import permutations

n = int(eval(input()))
xy = [list(map(int, input().split())) for _ in range(n)]
ans = 0
count = 0
for i in permutations(list(range(n)), n):
    for j in range(n - 1):
        ans += (
            (xy[i[j]][0] - xy[i[j + 1]][0]) ** 2 + (xy[i[j]][1] - xy[i[j + 1]][1]) ** 2
        ) ** 0.5
    count += 1
print((ans / count))

-N = int(eval(input())) -xy = [list(map(int, input().split())) for _ in range(N)] +n = int(eval(input())) +xy = [list(map(int, input().split())) for _ in range(n)] -l = list(permutations(xy, N)) -for i in l: -    for j in range(N - 1): -        ans += ((i[j][0] - i[j + 1][0]) ** 2 + (i[j][1] - i[j + 1][1]) ** 2) ** 0.5 -print((ans / len(l))) +count = 0 +for i in permutations(list(range(n)), n): +    for j in range(n - 1): +        ans += ( +            (xy[i[j]][0] - xy[i[j + 1]][0]) ** 2 + (xy[i[j]][1] - xy[i[j + 1]][1]) ** 2 +        ) ** 0.5 +    count += 1 +print((ans / count))