import sys
import math
import bisect
from heapq import heapify, heappop, heappush
from collections import deque, defaultdict, Counter
from functools import lru_cache
from itertools import accumulate, combinations, permutations, product

sys.setrecursionlimit(1000000)
MOD = 10 ** 9 + 7
MOD99 = 998244353

input = lambda: sys.stdin.readline().strip()
NI = lambda: int(input())
NMI = lambda: map(int, input().split())
NLI = lambda: list(NMI())
SI = lambda: input()
SMI = lambda: input().split()
SLI = lambda: list(SMI())
EI = lambda m: [NLI() for _ in range(m)]


def cross3(X, Y):
    return [X[(i+1)%3]*Y[(i+2)%3]-X[(i+2)%3]*Y[(i+1)%3] for i in range(3)]


def dist_P_from_plane_of_3points(Qs):
    Q01 = [Qs[1][i] - Qs[0][i] for i in range(3)]
    Q02 = [Qs[2][i] - Qs[0][i] for i in range(3)]
    R = cross3(Q01, Q02)
    a, b, c = R
    x, y, z = Qs[0]
    d = a*x + b*y + c*z
    return abs(d / math.sqrt(a**2+b**2+c**2))

def main():
    N = NI()
    # P = [int(s.replace(".", "")) for s in SLI()]
    P = list(map(float, SMI()))
    XYZ = []
    for _ in range(N):
        # xyz = [int(s.replace(".", "")) for s in SLI()]
        xyz = list(map(float, SMI()))
        xyz = [p-x for p, x in zip(P, xyz)]
        XYZ.append(xyz)

    ans = 0
    for i in range(N):
        for j in range(i+1, N):
            for k in range(j+1, N):
                ans += dist_P_from_plane_of_3points([XYZ[i], XYZ[j], XYZ[k]])

    # print(ans / 10**6)
    print(ans)


if __name__ == "__main__":
    main()