import java.io.*;
public class test
{
public static void main(String args[])
{
try
{
BufferedReader in=new BufferedReader(new InputStreamReader(System.in));
String str=in.readLine();
int length=str.length();
char []a=new char[length];
int j=0;
int seat=0;
for(int i=0;i<length;i++)
a[i]=str.charAt(i);
for(int i=0;i<length-1;i++)
{
j=i+1;
while(j<length-1)
{
if(a[i]==a[j])
{
seat=j+1;
for(int m=j;m<length-1;m++)
a[m]=a[m+1];
length--;
}
j=seat;
}
}
for(int i=0;i<length;i++)
System.out.print(a[i]+" ");
System.out.println();
}
catch(IOException e)
{
}
}
}