class MyVector{
  float u,v,w;

  MyVector(){
    u=v=w=0.;
  }
  MyVector(float x, float y, float z){
    u = x;
    v = y;
    w = z;
  }
  MyVector buildVector( MyPoint vert1, MyPoint vert2){
    u = vert2.x-vert1.x;
    v = vert2.y-vert1.y;
    w = vert2.z-vert1.z;
    return this;
  }
  float dot(MyVector v1){
    return v1.u*u+v1.v*v+v1.w*w;
  }
  void cross(MyVector v1){
    MyVector temp = new MyVector(0.,0.,0.);
    temp.u = v*v1.w - w*v1.v;
    temp.v = w*v1.v - u*v1.w;
    temp.w = u*v1.u - v*v1.v;
    u = temp.u;
    v = temp.v;
    w = temp.w;
  }

  void norm(){
    float t =  sqrt(u*u+v*v+w*w);
    u = u/t;
    v = v/t;
    w = w/t;
  }
  void print(){
    println("u:" + u);
    println("v:" + v);
    println("w:" + w);
  }
}