#define _GNU_SOURCE
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdio.h>

#define CHUNK_SIZE 40000000
#define LINES_CHUNK_SIZE 10000
#define BUF_SIZE 320000

void dump(char *buffer, int size) {
   while (size>0) {
     int w = write(1, buffer, size);
     buffer+=w;
     size-=w;
   }
}

static inline char * dumpstr(char *buffer, char *current, char *word, int len, int newline) {
  int capacity = buffer+BUF_SIZE-current;
  if (len > capacity) {
     dump(buffer, current - buffer);
     current = buffer;
  }
  if (len>8) {
    memcpy(current,word,len);
  } else {
    memcpy(current,word,8);
  }
  /*
  switch (len) {
    case 0: break;
    case 1: memcpy(current,word,1);break;
    case 2: memcpy(current,word,2);break;
    case 3: memcpy(current,word,3);break;
    case 4: memcpy(current,word,4);break;
    case 5: memcpy(current,word,5);break;
    case 6: memcpy(current,word,6);break;
    case 7: memcpy(current,word,7);break;
    case 8: memcpy(current,word,8);break;
    default: memcpy(current,word,len);break; 
  }*/
  current+=len;
  if (newline) {
    *current = '\n';
    current++;
  }
  return current;
}

int main() {
	// INPUT reading
	char *buf = malloc(CHUNK_SIZE);
	int size = CHUNK_SIZE;
	{
	  char *s = buf;
	  int left = CHUNK_SIZE;
	  while(1){
	  	int n = read(0, s, left);
	  	if(n == 0) break;
	  	s += n; left -= n;
	  	if(left == 0) {
                   int tmp = size;
	           size += CHUNK_SIZE;
		   left = CHUNK_SIZE;
	  	   buf=realloc(buf, size);
		   s = buf + tmp;
	  	}
	  }
	  *s = '\n';
	  *(s+1) = '\0';
	  //unlikely
	  if (size < s-buf+8) {
	     buf = realloc(buf, size+8);
	  }
	}

	char **w = NULL;
	ssize_t  *o = NULL;
	int k = 0;
	{
	  char *s = buf;
	  while (*s) {
  	     if (k % LINES_CHUNK_SIZE == 0) {
  	       w = realloc(w, (k+LINES_CHUNK_SIZE)*sizeof(ssize_t));
  	       o = realloc(o, (k+LINES_CHUNK_SIZE)*sizeof(ssize_t));
  	     }
	     w[k] = s;                                          // set offset 
	     while (*s != '\r' && *s != '\n' && *s != ' ') s++; // read word
	     o[k] = s-w[k];                                     // set length
	     k++;
	     while (*s == '\r' || *s == '\n' || *s == ' ') s++;  // read space characters
	  }
	}
	char out_buf[BUF_SIZE+8];
	char *s = out_buf;
	for(int i = 0; i < k; i+=2)
		for(int j = 1; j < k; j+=2){
			s=dumpstr(out_buf,s,w[i],o[i],0);
			s=dumpstr(out_buf,s,w[j],o[j],1);
		}
	dump(out_buf, s - out_buf);
	return 0;
}