N=int(eval(input()))

import math



XY=[[int(x) for x in input().rstrip().split()] for i in range(N)]



ans=0

for i in range(N):

  for j in range(N):

    if i<j:

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

bb=1

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

  bb*=i



print((2*ans/N))

N=int(eval(input()))

import math



XY=[[int(x) for x in input().rstrip().split()] for i in range(N)]



ans=0

for i in range(N):

  for j in range(N):

    if i<j:

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





print((2*ans/N))

N = int(eval(input()))
import math

XY = [[int(x) for x in input().rstrip().split()] for i in range(N)]
ans = 0
for i in range(N):
    for j in range(N):
        if i < j:
            ans += math.sqrt((XY[i][0] - XY[j][0]) ** 2 + (XY[i][1] - XY[j][1]) ** 2)
bb = 1
for i in range(1, N + 1):
    bb *= i
print((2 * ans / N))

N = int(eval(input()))
import math

XY = [[int(x) for x in input().rstrip().split()] for i in range(N)]
ans = 0
for i in range(N):
    for j in range(N):
        if i < j:
            ans += math.sqrt((XY[i][0] - XY[j][0]) ** 2 + (XY[i][1] - XY[j][1]) ** 2)
print((2 * ans / N))

-bb = 1 -for i in range(1, N + 1): -    bb *= i