import java.util.Scanner;


public class Main_yukicoder132 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        int n = sc.nextInt();

        double[] p = new double[3];
        for (int i = 0; i < 3; i++) {
        	p[i] = sc.nextDouble();
        }

        double[][] xyz = new double[n][3];
        for (int i = 0; i < n; i++) {
        	xyz[i][0] = sc.nextDouble();
        	xyz[i][1] = sc.nextDouble();
        	xyz[i][2] = sc.nextDouble();
        }

        double ret = 0;
        for (int i = 0; i < n; i++) {
            for (int j = i + 1; j < n; j++) {
                for (int k = j + 1; k < n; k++) {
                	double[] nn = cross(xyz[i], xyz[j], xyz[k]);

                	double d1 = -(nn[0] * xyz[i][0] + nn[1] * xyz[i][1] + nn[2] * xyz[i][2]);
//                	double d2 = nn[0] * xyz[j][0] + nn[1] * xyz[j][1] + nn[2] * xyz[j][2];
//                	double d3 = nn[0] * xyz[k][0] + nn[1] * xyz[k][1] + nn[2] * xyz[k][2];

//                	System.out.printf("%f %f %f\n", d1, d2, d3);

                	ret += dist(p, nn[0], nn[1], nn[2], d1);
                }
            }
        }

        System.out.println(ret);

        sc.close();
    }

    private static double dist(double[] p, double a, double b, double c, double d) {
    	double ret = Math.abs(p[0] * a + p[1] * b + p[2] * c + d);
    	ret /= Math.sqrt(a * a + b * b + c * c);

    	return ret;
    }

    private static double[] cross(double[] a, double[] b, double[] c) {
    	double[] ret = new double[3];

    	ret[0] = (b[1] - a[1]) * (c[2] - a[2]) - (b[2] - a[2]) * (c[1] - a[1]);
    	ret[1] = (b[2] - a[2]) * (c[0] - a[0]) - (b[0] - a[0]) * (c[2] - a[2]);
    	ret[2] = (b[0] - a[0]) * (c[1] - a[1]) - (b[1] - a[1]) * (c[0] - a[0]);

    	return ret;
	}
}