N=int(eval(input()))

L=[]

for i in range(N):

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

    L.append([x,y])

    

cnt=0

S=0

for i in range(N-1):

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

        cnt+=1

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

AVE=S/cnt

print((AVE*(N-1)))

        
N=int(eval(input()))

L=[]

for i in range(N):

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

    L.append([x,y])

D=[]

for i in range(N-1):

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

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

        D.append(d)

Ave=sum(D)/len(D)

print((Ave*(N-1)))
N = int(eval(input()))
L = []
for i in range(N):
    x, y = list(map(int, input().split()))
    L.append([x, y])
cnt = 0
S = 0
for i in range(N - 1):
    for j in range(i + 1, N):
        cnt += 1
        S += ((L[i][0] - L[j][0]) ** 2 + (L[i][1] - L[j][1]) ** 2) ** 0.5
AVE = S / cnt
print((AVE * (N - 1)))

N = int(eval(input()))
L = []
for i in range(N):
    x, y = list(map(int, input().split()))
    L.append([x, y])
D = []
for i in range(N - 1):
    for j in range(i + 1, N):
        d = ((L[i][0] - L[j][0]) ** 2 + (L[i][1] - L[j][1]) ** 2) ** 0.5
        D.append(d)
Ave = sum(D) / len(D)
print((Ave * (N - 1)))

-cnt = 0 -S = 0 +D = [] -        cnt += 1 -        S += ((L[i][0] - L[j][0]) ** 2 + (L[i][1] - L[j][1]) ** 2) ** 0.5 -AVE = S / cnt -print((AVE * (N - 1))) +        d = ((L[i][0] - L[j][0]) ** 2 + (L[i][1] - L[j][1]) ** 2) ** 0.5 +        D.append(d) +Ave = sum(D) / len(D) +print((Ave * (N - 1)))