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.

Restricciones

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

Ejemplos

Entrada:
n = 14

Salida esperada:
expected = 3

Entrada:
long long n = 14;

Salida esperada:
long long expected = 3;

Entrada:
long n = 14;

Salida esperada:
long expected = 3;

Entrada:
n = 7

Salida esperada:
expected = 1

Entrada:
long long n = 7;

Salida esperada:
long long expected = 1;

Entrada:
long n = 7;

Salida esperada:
long expected = 1;

Referencias

Este reto está adaptado para CodeUtility. Sigue el enunciado y las restricciones indicadas arriba.

• Removing Digits — 1637