变换次数

import java.util.Scanner;

public class Main {

    public static String Mul(String str){
        int res = 1;
        char[] ch = str.toCharArray();
        for (int i = 0 ; i < ch.length ; i++){
            res *= (int)(ch[i] - '0');
        }
        return String.valueOf(res);
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        StringBuffer str = new StringBuffer(in.next());
        int res = 0;
        if (str.length() == 1){
            res = 0;
        }else{
            while(true){
                String tmp = Mul(str.toString());
                if (tmp.length() != 1){
                    res++;
                    str.delete(0, str.length());
                    str.append(tmp);
                }else{
                    res++;
                    break;
                }               
            }
        }
        System.out.println(res);
        in.close();
    }

}