Subtract Digits to Reach Zero

At each step, choose a nonzero decimal digit currently present in the number and subtract that digit. Digits are taken from the new value after every step. Find the minimum number of steps needed to reach zero.

Implement removing_digits(n).

Input

n: The positive starting number.

Output

Return the fewest subtraction steps.

Contraintes

1 ≤ n ≤ 1,000,000. Subtracting zero is not a useful move and is excluded.

Exemples

Entrée :
n = 14

Sortie attendue :
expected = 3

Entrée :
long long n = 14;

Sortie attendue :
long long expected = 3;

Entrée :
long n = 14;

Sortie attendue :
long expected = 3;

Entrée :
n = 7

Sortie attendue :
expected = 1

Entrée :
long long n = 7;

Sortie attendue :
long long expected = 1;

Entrée :
long n = 7;

Sortie attendue :
long expected = 1;

Références

Ce défi a été adapté pour CodeUtility. Suivez l'énoncé et les contraintes ci-dessus.

• Removing Digits — 1637