Олимпиадный тренинг

Задача 39776. 16-23


Задача

Темы: ЕГЭ
The algorithm for calculating the value of the functions F(n)  and G(n), where n – natural number, given by the following relations:

F(n) = n + 10 if n < 10;
F(n) = n % 10 + G(F(n/10)), otherwise;
G(n) = n + 10 if n < 10;
G(n) = n % 10 + G(n/10), otherwise;

Determine how many different values ​​the F(n)function takes for all n smaller 1000000?
Sign / - means integer division operation. 
Sign % - means the operation of calculating the remainder of the division of two integers.