import java.io.IOException;

/*
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 * and open the template in the editor.
 */
/**
 *
 * @author cteam32
 */
public class easy {

    public static void main(String[] args) throws IOException {

        String cislo;
        while (!(cislo = nextLine()).equalsIgnoreCase("0")) {
            int soucet = sectiSlozky(cislo+"");
            int c2 = Integer.parseInt(cislo);
            int c = 11;
            while(true) {
                if (sectiSlozky((c2*c)+"")==soucet) {
                    System.out.println(c);
                    break;
                }else{
                    c++;
                }
            }

        }

    }

    public static int sectiSlozky(String str) {
        int soucet = 0;
        for (int i = 0; i < str.length(); i++) {
            soucet += Byte.parseByte(str.charAt(i)+"") ;//Math.pow(Byte.parseByte(str.charAt(i) + ""), i + 1);
        }
        return soucet;
    }

    public static String nextLine() throws IOException {
        int z;
        String ret = "";
        while ((z = ((char) (System.in.read()))) != '\n') {
            ret += (char) z;
        }
        return ret;
    }
}