#include <stdio.h>

struct punkt{
  int x;
  int y;
  struct punkt *jargmine;
};

int main(void){
  struct punkt p1, p2, p3, *p;
  p1.x=17;  p1.y=23;
  p2.x=21;  p2.y=45;
  p3.x=46;  p3.y=47;
  p1.jargmine=&p2;
  p2.jargmine=&p3;
  p3.jargmine=NULL;
  p=&p1;
  while(p!=NULL){
    printf("x=%d\n", p->x);
    p=p->jargmine;
  }
  return 0;
}