提取不重复的整数

/*
思路：利用ArrayList的contains方法,记录每一个不重复的整数
*/
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
public class Main{
    public static void main(String[] args)throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str = br.readLine();
        ArrayList<String> list = new ArrayList<>();
        int sum = 0;
        for(int i = str.length()-1;i>=0;i--){
            String temp = String.valueOf(str.charAt(i));
            if(!list.contains(temp)){
                list.add(temp);
                sum = sum*10 + Integer.parseInt(temp);
            }
            else
                continue;
        }
        System.out.println(sum);

    }
}