#include <stdio.h>
#include <math.h>
#include <malloc.h>

typedef struct point {
  double x,y,z;
} POINT;

typedef struct ray {
  POINT p,v;
} RAY;

typedef struct polygon {
  int n;
  POINT *v;
} POLYGON;

RAY *make_ray(POINT eye, int n, int x, int y);
POINT *ray_poly_intersect(RAY *ray, POLYGON *polygon);

main () {
  RAY *ray;
  POLYGON poly;
  POINT eye,*hitpoint;
  int i,x,y;
  int n;

  scanf("%lf%lf%lf",&eye.x,&eye.y,&eye.z);
  scanf("%d",&n);
  scanf("%d%d",&x,&y);
  scanf("%d",&poly.n);
  poly.v = (POINT *)malloc(poly.n*sizeof(POINT));
  for (i=0; i<poly.n; i++) {
    scanf("%lf%lf%lf",&poly.v[i].x,&poly.v[i].y,&poly.v[i].z);
  }
  ray = make_ray(eye,n,x,y);

  hitpoint = ray_poly_intersect(ray,&poly);
  if (hitpoint == NULL)
    printf("no intersection\n");
  else
    printf("intersection at (%8.3lf %8.3lf %8.3lf)\n",
	   hitpoint->x,hitpoint->y,hitpoint->z);
}

/*
 * You must change these functions to do the right thing
 */

RAY *make_ray(POINT eye, int n, int x, int y) {
  RAY *ray = (RAY *)malloc(sizeof(RAY));

 /*
  * These are arbitrary values.
  *  You'll have to set all of them correctly yourself.
  */ 

  ray->p.x = 0.0;
  ray->p.y = 0.0;
  ray->p.z = 0.0;

  ray->v.x = 0.0;
  ray->v.y = 0.0;
  ray->v.z = 1.0;

  return ray;
}

POINT *ray_poly_intersect(RAY *ray, POLYGON *polygon) {
  return NULL;
}