#include <stdio.h>
#include <stdlib.h>
#define KORAK 10

typedef struct Datum{
  int dan;
  int mesec;
  int godina;
} datum;

void greska(){
  fprintf(stderr, "-1\n");
  exit(EXIT_FAILURE);
}
int provera(datum d){
  return d.dan < 1 || d.dan > 31 || d.mesec < 1 || d.mesec > 12
      || d.godina < 0 || d.godina > 9999;
}

int cmp(const void * ptr1, const void *ptr2){
  const datum * d1 = ptr1;
  const datum * d2 = ptr2;

  int r = d1->godina - d2->godina;

  if(r == 0){
    r = d1->mesec - d2->mesec;
    if(r == 0){
      return d1->dan - d2->dan;
    }
    return r;
  }

  return r;
}

int main(int argc, char const *argv[]) {
  FILE * ulaz = fopen("datum.txt", "r");
  if(ulaz == NULL){
    greska();
  }
  int n;
  n = KORAK;

  datum* d = malloc(n*sizeof(datum));
  if(d == NULL){
    greska();
  }
  int i = 0;
  while (fscanf(ulaz, "%d.%d.%d.", &d[i].dan, &d[i].mesec, &d[i].godina) != EOF) {
    if(provera(d[i])){
      greska();
    }
    i++;
    if(i == n){
      n += KORAK;
      d = realloc(d, n*sizeof(datum));
      if(d == NULL){
        greska();
      }
    }
  }
  fclose(ulaz);
  n = i;

  qsort(d, n, sizeof(datum), cmp);

  for(i = 0; i < n ; i++){
    printf("%d.%d.%d.\n", d[i].dan, d[i].mesec, d[i].godina );
  }
  free(d);
  return 0;
}