Whenever someone suggests to make an input for a phone number with pre-defined number, stand up and oppose! Computers are for humans, not the other way around.
Yandex Drive wants a number with 10 digits.
Ok, my Norwegian number has 10 digits. Nope, it's not valid and they won't tell me what is the problem. On the other hand, Yandex Drive is a service in Russia. My Russian number has 11 digits in it. Bummer!