HDOJ-ACM1013(JAVA)

import java.util.*;

import java.io.*;

public class Main{

    public static void main(String[] arg){
        Scanner scan = new Scanner(new BufferedInputStream(System.in));
        String s;
        while(true){
            s=scan.next();
            char[] cs = s.toCharArray();
            if(cs[0] == ‘0‘){
                break;
            }
            if(cs.length==1){
                System.out.println(s);
                continue;
            }
            System.out.println(getSum(cs));
        }
        scan.close();
    }

    static int getSum(char[] cs){
        int sum = 0;
        while(cs.length!=1){
            sum = 0;
            for(int i = 0 ; i != cs.length ; i ++ ){
                sum = cs[i]-‘0‘ + sum;
            }
            cs = String.valueOf(sum).toCharArray();
        }
        return sum;
    }
}