using System;
using System.IO;
using System.Text;
using System.Linq;
using System.Diagnostics;
using System.Collections.Generic;
using Enu = System.Linq.Enumerable;

class Program
{
    void Solve()
    {
        int N = reader.Int();
        var P = Enu.Range(0, 3).Select(i => reader.Double()).ToArray();
        var Qs = Enu.Range(0, N).Select(i => Enu.Range(0, 3).Select(j => reader.Double()).ToArray()).ToArray();
        double ans = 0;

        for (int a = 0; a < N; a++)
            for (int b = a + 1; b < N; b++)
                for (int c = b + 1; c < N; c++)
                    ans += Dist(P, Qs[a], Qs[b], Qs[c]);

        Console.WriteLine(ans);
        Console.ReadLine();
    }

    double Dist(double[] P, double[] Q1, double[] Q2, double[] Q3)
    {
        double x1 = Q1[0], y1 = Q1[1], z1 = Q1[2];
        double x2 = Q2[0], y2 = Q2[1], z2 = Q2[2];
        double x3 = Q3[0], y3 = Q3[1], z3 = Q3[2];
        double a = (y2 - y1) * (z3 - z1) - (y3 - y1) * (z2 - z1);
        double b = (z2 - z1) * (x3 - x1) - (z3 - z1) * (x2 - x1);
        double c = (x2 - x1) * (y3 - y1) - (x3 - x1) * (y2 - y1);
        double d = -(a * x1 + b * y1 + c * z1);
        return Math.Abs(a * P[0] + b * P[1] + c * P[2] + d) / Math.Sqrt(a * a + b * b + c * c);
    }




    static void Main() { new Program().Solve(); }
    Reader reader = new Reader(Console.In);
    class Reader
    {
        private readonly TextReader reader;
        private readonly char[] separator = { ' ' };
        private readonly StringSplitOptions removeOp = StringSplitOptions.RemoveEmptyEntries;
        private string[] A = new string[0];
        private int i;

        public Reader(TextReader r) { reader = r; }
        public bool HasNext() { return Enqueue(); }
        public string String() { return Dequeue(); }
        public int Int() { return int.Parse(Dequeue()); }
        public long Long() { return long.Parse(Dequeue()); }
        public double Double() { return double.Parse(Dequeue()); }
        public int[] IntLine() { var s = Line(); return s == "" ? new int[0] : Array.ConvertAll(Split(s), int.Parse); }
        public int[] IntArray(int N) { return Enumerable.Range(0, N).Select(i => Int()).ToArray(); }
        public int[][] IntGrid(int H) { return Enumerable.Range(0, H).Select(i => IntLine()).ToArray(); }
        public string[] StringArray(int N) { return Enumerable.Range(0, N).Select(i => Line()).ToArray(); }
        public string Line() { return reader.ReadLine().Trim(); }
        private string[] Split(string s) { return s.Split(separator, removeOp); }
        private bool Enqueue()
        {
            if (i < A.Length) return true;
            string line = reader.ReadLine();
            if (line == null) return false;
            if (line == "") return Enqueue();
            A = Split(line);
            i = 0;
            return true;
        }
        private string Dequeue() { Enqueue(); return A[i++]; }
    }
}