import sequtils,strutils,math

type
    vector = tuple[x, y, z : float64]

proc `+`(a, b : vector) : vector =
    result = (a.x + b.x, a.y + b.y, a.z + b.z)
    
proc `-`(a, b : vector) : vector =
    result = (a.x - b.x, a.y - b.y, a.z - b.z)

proc `*`(a : float64, b : vector) : vector =
    result = (a * b.x, a * b.y, a * b.z)

proc `*`(a, b : vector) : float64 =
    result = a.x * b.x + a.y * b.y + a.z * b.z

proc abs(a : vector) : float64 =
    if a.x > 0.0001 or a.x < -0.0001:
        result = abs(a.x) * sqrt(1 + pow(a.y / a.x, 2) + pow(a.z / a.x, 2))
    elif a.y > 0.0001 or a.y < -0.0001:
        result = abs(a.y) * sqrt(1 + pow(a.z / a.y, 2))
    else:
        result = abs(a.z)
        
proc `=~`[T](a, b : T) : bool =
    if abs(a - b) < 0.00001:
        return true
    else:
        return false
        
proc solve2eq(a, b : array[3, float64]) : tuple[x, y : float64] =
    var a = a
    var b = b
    if b[0] == 0:
        result.y = b[2] / b[1]
        result.x = (a[2] - a[1] * result.y) / a[0]
        return
    for i in countdown(2, 0):
        b[i] = b[i] / b[0] * a[0]
    for i in 0..2:
        b[i] -= a[i]
    
    result.y = b[2] / b[1]
    result.x = (a[2] - a[1] * result.y) / a[0]
    return

proc hypotM(a, b, c : vector) : float64 =
    var
        n, k : float64
        t, s, d : vector
    t = c - a
    s = b - a
    var A,B : array[3, float64]
    A = [t * t, t * s, - (a * t)]
    B = [t * s, s * s, - (a * s)]
    (n, k) = solve2eq(A, B)
    d = n * t + k * s + a
    return abs(d)


var
    N = stdin.readline.parseInt
    P : seq[float64] = stdin.readline.split.map(parsefloat)
    T = newSeqWith(N, newSeq[float64](3))

for n in 0..<N:
    T[n] = stdin.readline.split.map(parsefloat)
    
var ans : float64
var p : vector = (P[0], P[1], P[2])
for i in 0..<N:
    var a : vector = (T[i][0], T[i][1], T[i][2])
    a = a - p
    for j in (i + 1)..<N:
        var b : vector = (T[j][0], T[j][1], T[j][2])
        b = b - p
        for k in (j + 1)..<N:
            var c : vector = (T[k][0], T[k][1], T[k][2])
            c = c - p 
            ans += hypotM(a, b, c)
echo formatBiggestFloat(ans, ffDecimal)