#include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #ifndef BUFSIZ
  # define BUFSIZ 4096
  #endif
  
  #undef BUFSIZ
  # define BUFSIZ 64
  int main (void)
  {
  	short ibuff[BUFSIZ], obuff[BUFSIZ];
  	int rc, i, len;
  
  	while ((rc = read (0, ibuff, sizeof (ibuff))) > 0) {
  		memset (obuff, 0, sizeof (obuff));
  		for (i = 0; i < (rc + 1) / 2; i++) {
  			obuff[i] = ibuff[i ^ 1];
  		}
  
  		len = (rc + 1) & ~1;
  
  		if (write (1, obuff, len) != len) {
  			perror ("read error");
  			return (EXIT_FAILURE);
  		}
  
  		memset (ibuff, 0, sizeof (ibuff));
  	}
  
  	if (rc < 0) {
  		perror ("read error");
  		return (EXIT_FAILURE);
  	}
  	return (EXIT_SUCCESS);
  }