l01ex3031.java

import java.util.Scanner;

class Main {
  public static int somaDigitos(int x) {
    int resto, soma = 0;
    
    while (x!=0) {
      resto = x%10;
      soma = soma + resto;
      x = x/10;
    }
    return soma;
  }
  
  public static void main(String[] args) {
    int x, persistencia = 0;
    Scanner leitor = new Scanner(System.in);
    
    x = leitor.nextInt();
    
    while (x>9) {
      x = somaDigitos(x);
      persistencia = persistencia + 1;
    }
    System.out.println(persistencia);

  }
}