#include<stdio.h>
#include<string.h>
char prov[20],text[10000000],a[50000][20];

int main ()
{
long i,poz;
FILE *f=fopen("abc2.in","r");
fgets(text,1000000,f);
poz=0;
while (!feof(f))
      {
      fgets(prov,20,f);
      for (i=0;i<=poz;++i)
	  if ( strcmp(a[i],prov) == 1 )
	     i=poz+2;
      if (i!=poz+2)
	 {
	 strcpy(a[++poz],prov);
	 //printf("%s\n",a[poz]);
	 }
      }
return 0;
}