华为 9

package NiukeBrush;
import java.util.Iterator;
//排序与查重
import java.util.LinkedHashSet;
import java.util.Scanner;
import java.util.Set;

//改进做法
public class Huawei9next {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		//键盘输入
		Scanner sc=new Scanner(System.in);
		String str=sc.nextLine();
		Set<Character> set=new LinkedHashSet<>();
		char[] ch1=str.toCharArray();
		for(int i=ch1.length-1;i>=0;i--)
		{
			set.add(ch1[i]);
		}
		Iterator it=set.iterator();
		while(it.hasNext())
		{
			System.out.print(it.next());
		}


	}

}