F1 !!! F1 !!!

Dear colleagues,

Can anybody, please, explain me the condition of the problem with simple tests?

I didn’t understand given sample.

Monks were told to write all the integers starting from the smallest integer that was not a substring of that string.

If 11 was the initial string. Assuming integers with leading zeroes are not accepted, monks would start from 0, then 2 (since 1 is a substring of 11)

That’s why, if the initial string was 11, monks would have written 02345678910, am I wrong?

Could anybody please explain me the condition of the problems?

Thanks,