public class Vec{
    private double x,y,z;

    public Vec (double a, double b, double c){
	x = a;
	y = b; 
	z = c;
    }

    public double dot (Vec w){
	return this.x * w.x + this.y * w.y + this.z * w.z;
    }

    public Vec cross (Vec w){
	double newX = this.y * w.z - this.z * w.y;
	double newY = this.z * w.x - this.x * w.z;
	double newZ = this.x * w.y - this.y * w.x;
	return new Vec (newX, newY, newZ);
    }

    public double length(){
	return Math.sqrt (this.dot(this));
    }

    public String toString(){
	return "(" + this.x + "," + this.y + "," + this.z + ")";
    }
}