#include<iostream.h>
#include<string.h>

void main()
{ char s[256];
  int i,j, gasit;
  cin.get(s,256);
  for(i=0;i<strlen(s);i++)
	if(s[i]>='a' && s[i]<='z')
		{ gasit=0;
		  for(j=0;j<i;j++)
			if(s[i]==s[j]) gasit=1;
		  if(!gasit) cout<<s[i]<<" ";
		}
}