import java.util.*;
import java.io.*;

public class generate{
   public static void main(String[] args) throws Exception{
      BufferedReader in = new BufferedReader(new FileReader(new File("generate.in")));
      
      String a = in.readLine();
      int tmp;
      
      LinkedList<String> values = new LinkedList<String>();
      
         
      while(!a.equals("0")){
         values = new LinkedList<String>();
         values.add(a);
         while(true){
            tmp = Integer.parseInt(a)*Integer.parseInt(a);
            a = "" + tmp;
            while (a.length() < 8)
               a = "0" + a;
            
            a = a.substring(2,6);
//            System.out.println(a);
               
            if (values.contains(a)) break;
            values.add(a);
         }        
         System.out.println(values.size());
         a = in.readLine();
      }   
   }
}