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)]



ans = 0

for i in range(n):

  for j in range(n):

    if i == j: continue

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

print((ans/n))
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)]
ans = 0
for i in range(n):
    for j in range(n):
        if i == j:
            continue
        ans += ((xy[i][0] - xy[j][0]) ** 2 + (xy[i][1] - xy[j][1]) ** 2) ** 0.5
print((ans / n))

-from itertools import permutations - -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)) +for i in range(n): +    for j in range(n): +        if i == j: +            continue +        ans += ((xy[i][0] - xy[j][0]) ** 2 + (xy[i][1] - xy[j][1]) ** 2) ** 0.5 +print((ans / n))