#include <string.h>
#include <stdio.h>
#include <stdlib.h>

#define MAX_LINES 1024
#define MAX_LINE_LENGTH 1024

void swap(char *v[], int i, int j)
{
   char *temp;
   temp = v[i];
   v[i] = v[j];
   v[j] = temp;
}

void sort(char *v[], int left, int right)
{
   int i, last;
   if (left >= right)
      return;
   swap(v, left, (left + right) / 2);
   last = left;
   for (i = left+1; i <= right; i++)
      if (strcmp(v[i], v[left]) < 0)
         swap(v, ++last, i);
   swap(v, left, last);
   sort(v, left, last-1);
   sort(v, last+1, right);
}

int main(int argc, char *argv[])
{
   char *ppcArray[MAX_LINES];
   char pcLine[MAX_LINE_LENGTH];
   int iLineCount = 0;
   int i;

   while (fgets(pcLine, MAX_LINE_LENGTH, stdin) != NULL)
   {
      if (iLineCount == MAX_LINES)
         break;
      ppcArray[iLineCount] = (char*)malloc(strlen(pcLine));
      strcpy(ppcArray[iLineCount], pcLine);
      ++iLineCount;
   }
   
   sort(ppcArray, 0, iLineCount - 1);

   for (i = 0; i < iLineCount; ++i)
      fputs(ppcArray[i], stdout);

   fflush(stdout);
   
   fprintf(stderr, "Line count:  %d.\n", iLineCount);

   return 0;
}