#include <stdio.h>

struct punkt{
  int x;
  int y;
};

int main(void){
  struct punkt p1;
  FILE *f;
  p1.x=17;
  p1.y=23;
  f=fopen("punktid.dat", "wb");
  fwrite(&p1, sizeof(struct punkt), 1, f);    
  p1.x=21;
  p1.y=45;
  fwrite(&p1, sizeof(struct punkt), 1, f);    
  fclose(f);
  return 0;
}